Loss of appetite either tired or don't like the food. I'm scared. What should I do?

I was diagnosed with ADHD a little longer than half a year now. Been taking meds, I know how they supress the appetite and all. I always struggled with food before, since I was little, all the issues with smell, texture, taste... Too picky all the times, easy to gag, even remembering some smells or textures. Also I have this thing to all of the sudden get nauseous if smth is close to my neck, scarf, turtleneck, facemask, necklase. But it comes for a few minutes, i breathe very carefully and it goes away. I noticed it happening frequently when i was in 11th grade. Well, it wasn't particularly me, i just remember my friends saying "what is wrong with you?" 😂. Still don't know if that is psychological (sudden gagging for no reason) or physiological.

So, about my eating issue. For the most time it was fine, at first, with eating. I had loss of appetite because of stimulant and then at the evening i would get extremely hungry. But now its not the case. I feeling super tired all the time. Not sure if its just ADHD paralysis or smth else, maybe even lack of calories doing it. I used to get excited to go to a lab, but now i just tired and want to be at go, lay in a bed all day, because of fatigue. I used to skip lunch a lot before, either because i couldn't manage the time, or i was just very focused on my work; and theres this thing that i feel like i need to prove everyone that i am productive and need to do a lot (synthesize a lot of compounds in short time to be exact; i've been told before, more than a year ago, way before that i work too slow, but maybe i just need to get used to it and will become like others. But i still feel like i'm not fast enough).

Now I feel, remember when to have a lunch, can organize my time, but the problem is eating by itself. It's not solely medication problem, i feel similarly on weekends when i take a brake too. And on top of that, sleep is a big issue as well. I basically don't want to sleep nor eat, and too tired to do anything i would enjoy.

What should i do first. Take a blood test, maybe there's a deficiency of some sorts? If its psychological I don't know where's the problem, what should i tell to the terapist, "eating is a hassle, please help"? 😂 I'm so tired of being tired! And I can not stop taking stimulants, I would fall into anxiety again if I stop; I am terrified of mistakes. And stimulants also gives me a push, a voice "JUST DO IT!", and peace and clarity.