Are you medicated? One of my boys has ADHD and it was life changing. When I was a kid ADD as they called it then was highly stigmatized because the meds turned you into a zombie, it's not the case anymore. Basically zero side effects other than appetite loss during lunch.
Isn't ADHD medication basically amphetamine? I experimented when I was younger and it wasn't nice stuff. Couldn't sleep properly afterwards, and loos of appetite (I am already pretty skinny).
My son takes Concerta which is an extended release drug that basically gives you the minimum viable amount over the course of about 8 hours. By late afternoon it's gone, but it gets him through school just fine. He eats a huge breakfast and dinner so his mostly ignored lunches aren't an issue. No problems with sleep and he's definitely not "high" while taking it. It just balances him out to where he should be.