Waking up with anxiety after 3-5 hours of sleep is because you are building up cortisol (stress hormone) levels while you sleep to the point where they wake you up. See a counselor and a doctor. You need both of you want lasting improvements. I have a rather severe anxiety disorder, waking up anxious in the middle of the night was once a nightly ritual, now it's pretty rare, only when something particularly anxiety inducing is going on.
Humans aren't evolved to be great at stuff on their own. In the hunter-gatherer days we couldn't hunt large animals alone, but required a group effort. We couldn't stay safe from predation or survive a cold winter as an individual. So we formed groups. Expulsion from the group meant certain death. So we evolved with a survival instinct that screams "YOU WILL DIE IF YOU OFFEND SOMEONE" that is a bit of an over reaction for today's society, but here we are.
Its really hard to day without more information. You should talk to a doctor. Some other things that could be causing this that noone else has mentioned yet(I can't tell if this applies for you or not based on your post):
not enough exercise
vitamin d/c deficiencies (you can take supplements of vitamin d in winter time)
bad gut microbiome. Try to eat a variety of vegtables as well as prebiotics (fibre, oats) and probiotics (yogurt, kefir,, sourdough ect).
try to get regular sleep. I know this is your problem but there may be some things you can do like have a set bedtime, no screens for a while before bed.
Remember that many people have had similar problems and overcome them. You will just need to work out what works for you. Good luck.