Nausea on HRT? (MtF)

I'm a trans woman, and I've been experiencing pretty annoying levels of nausea recently -- like, daily, for a few months. It's not too disruptive, but I get hungry really sporadically, and I spend the rest of the time feeling vaguely queasy. I'm wondering if it's at all related to the drug cocktail I'm on.

I've been on HRT for about 2 years now. I take estradiol (4 mg/day orally) and spironolactone (100 mg/day). I get my hormone levels checked regularly at a clinic. The spiro used to be 50 mg/day, but I had to up the dose after my testosterone levels started creeping back up several months ago.

The T uptick seemingly coincided with when I started taking bupropion for depression. My T levels are back in range, and I've since switched out the bupropion for lamotrigine (a mood stabilizer). But now I have all this nausea.

Despite what I've described, my HRT prescriber and my psychiatrist both insist that this drug combination shouldn't be causing nausea, nor the jump in T levels. So, it's a mystery, and quite a frustrating one. I feel like I'm a big bag of pills that's been shaken up until it's good and dizzy.

Not sure if anyone can relate to this -- how many depressed trans women are there out there, anyway? But if you have any advice, I'm all ears.