I don't feel rewarded for anything "good" I do

One of the essential features of ADHD is the rapid attenuation of the reward system, leading to a biological resistance to the "dopamine rush" that neurotypical people feel. (For me, it manifests most clearly in the fact that I have never in my life felt anything like the "runner's high" after exercise, although every neurotypical person I've spoken to says they feel refreshed, rejuvinated and pleasantly tired afterwards.)

This stems from the fact that the built-in reward system (the positive emotional response to performing/completing a task) attenuates very quickly in people with ADHD. By that I mean that while the response happens, it very quickly drops back to zero. Much faster than for people without ADHD.

This, I suspect, is one of the fundamental aspects of ADHD and why it's characterized by attention deficit and hyperactivity. Hyperactivity happens because in order to maintain the effects of the reward system we have to do and do and go go go over and over and over again. And we have attention deficit because our interest in any given thing drops extremely quickly, since the reward of experiencing it goes away almost immediately.

Not sure it'll work for you, but I managed to keep going with some habits (after they stop being motivating themselves) by being excited about what I could do after, "as soon as I'm done with my shower I can lie in bed and watch a YouTube while I get dry" or "after I finish my lunch I can have some cake". It seems to trick me into dopamine anticipation, and it's easier to switch around what the motivating fun activity is than try to find ways of making chores exciting in themselves.

Everybody is saying how the goal of these things isn't to make you feel good, but here's the thing: people keep telling me how "you'll feel better once you've done it" for all kinds of shit as the ultimate reason to "just do it". And then I (somehow manage to) do it and I don't. That's messing with my head and I suspect OP's as well.

If you don't do the important things in life you'll die. Your genes built the dopamine system to make sure you'll do those things. Your dopamine system doesn't function correctly. When you do a life sustaining thing, your broken dopamine system says, "meh, that was a waste of time, don't do that again or you'll die. Do something that does give dopamine."

Here's my hack. Give your brain dopamine. Figure out the things that engage you and make you feel good. If you're engaged and feeling good, it's because the dopamine is flowing. I like reading, video games, TV, and interesting complex problems. Right after I do a boring task, I reward myself with some dopamine. I play a game or I work on an interesting problem. I treat my brain like a labrador. Good boy have a treat. The bigger the task the bigger the reward.

Slightly less helpful but still good is affirmations. When you do something good, take a moment to recognize it, just to yourself. "I cleaned my room, which is good. I should feel good about it." It sounds corny, but it helps.

Everything you are saying makes perfect sense. Many of the tasks we do are simply because they are necessary. You get a boost from the schedule when it is 'new' but as time goes on that fades. Habit is a powerful tool. Keep to the same things at the same time making things automatic.

It sounds like you may not just have adhd, but your mention of feeling 'nothing' sounds a bit like a depressive symptom. You may want to talk with a doctor. If it is depression there are medications that start to get you on the right track.

I’m not a neurologist, but my understanding is that ADHD is essentially caused by reduced reception to dopamine, the chemical the brain uses to signal feelings of pleasure or satisfaction. So while neurotypical folks might clean their room and have that “job well done” feeling, folks with ADHD may not get that reinforcement.

You’ve probably heard all that before, but I’m outlining it to set up the mechanics of the potential solution I’ll suggest: bribery! Find a simple reward that you can make contingent on completing your tasks. Whatever works best for you. Maybe when you finish your homework you can eat a piece of candy, or you can make an accomplishment chart like in preschool and fill it with the sparkliest stickers you can find. Personally I use an app called Habitica that reframes to-do lists as RPG-style quests; completing them gives you experience points and gold to level up your character and get them little outfits. It sounds silly, but those kinds of more-tangible rewards can sometimes be more effective at giving you that positive reinforcement.

Another thing I’ve found to be helpful is putting on music while I’m doing otherwise-boring tasks to make them more enjoyable.

Unfortunately it can take a lot of trial-and-error to find techniques that work for you, but hopefully these are helpful.

One other thing to note is that if you’re not enjoying the vast majority of activities, including things that you used to enjoy, then you might be experiencing anhedonia, which can be a symptom of depression. To be clear, I can’t diagnose you but if that sounds like what you’re feeling it’d be a good idea to bring it up to your therapist so they can evaluate you.

Here's the thing, you do these things more for self maintenance rather than for it to feel good. Brush your teeth and floss now so they don't rot when you're older. And that comes faster than you think. Like I was eating dinner at my neighbor's house on his 60th birthday and he was dealing with painful root canals. (But my sister had to deal with those in her teens)

Homework SUCKS, but it teaches you discipline for yourself. Doing parts you don't quite enjoy just to get the job done. Which is insanely important for every single work ethic you do in your future. I know so many 3d artists who are incredible, but have the attention span worse than rats. So they don't go anywhere and constantly need to be told to stay focused.

A clean room is a clean mind. Having a messy room to wake up to is fine at first. But it can tend to get worse and spread throughout the rest of the house over time and 1 small task each day turns into a mountainous multi-day cleanup. (My mother is a hoarder of projects and stuff. 2 rooms completely unusable in the house and she leaves her tools all over the place without making a habit of putting stuff back. I never know where anything is)

It's the same for food. You eat the damn vegetables now to get a palette for them or you will suffer obesity by fast food or whatever. Which leads to lack of energy and always feeling fatigued. (Which I'm currently dealing with and only now just got to liking Broccoli. I'm 29)

As someone who decided to only live for things that I actually care about and even made my own job as a 3d animator, maintenance and discipline show up in places you don't expect and you'll be thankful you built it up beforehand. The things that make me feel good are my choices in what I work on, the dream that I strive for, and the fact that I carry a sense of quality and discipline at some points to be able to be more ambitious than others because I will carry out tough tasks rather than avoid them even when they don't make me feel rewarded.

Lastly let's talk about the schedule. Super important to even have one despite friends being all, "Let's go out late at night til 4am". Let's see their attention span when they're older. Well the schedule helps you get food in your body that you might forget to do because you're so focused, or even overly eat. Sleep is incredibly important, but you know something is wrong when you wake up and already feel tired. You may break the schedule to however you want after school, which is really nice, but if you create your own job in art then you'll have to apply one to yourself or weeks or months will fly by and you're stuck on the same project without focus.

Also, take notes YOUR way. Forget standardized notes. Just write down whatever helps you remember things in the way you do. School usually forces tests without notes, but all work and even important conversations outside of school is all about taking notes and rereading them. Learn any way you can to enjoy that part! I have my own Discord server for all kinds of notes I take that get categorized. I also have a fast notes page in my phone's home screen because my memory is just bad. And that's OK, because I take great notes!

You don't do the necessary work because it feels good. You do the necessary work because it will pay you back in the future (you do your laundry today so that you can wear clean clothes tomorrow).

You do the things that feel good as a self-reward after doing the necessary work.

I'm not even sure if I even feel trully happy about doing all of my responsibilities.

It doesn't feel as if a burden has been lifted of my shoulder.

It doesn't feel as if I were "refreshed" or more energetic after I do all of these.

I think the expectation that it should feel good immediately is actually hurting you.