Forgive the slightly clickbait-y title.

For context, a doctor diagnosed me with ADHD when I was eight (so around seventeen years ago) and I've been taking stimulants pretty much every day (with some more recent exceptions) ever since. On my first day of taking Focalin, I didn't feel different at all, but later found out my teachers called my parents that day to say I was a completely different student at school that day. Since then I've found Focalin to mostly feel like a very good cup of a caffeinated beverage, but sometimes not much of anything. I have had side-effects from it.

Fast forward to this year and the DEA's mess starts effecting my ability to get Focalin. I have a rough couple of months where I don't take any stimulants at all, but I don't feel overly different, things are just harder and I slip more often. My psychiatrist recommends I switch to Cotempla, says it's very similar to Focalin. Well, I've been on Cotempla for a few weeks now, and if anything, I think things have gotten worse. Work is very hard to be present for, I'm making more careless mistakes than usual, and I'm very sleepy more often than not despite getting a ton of sleep every night (though I had issues with fatigue while on Focalin as well). But again, I don't necessarily feel different. Wondering if there are ways to gauge the efficacy of a medication in situations like this?

TL;DR: I was on Focalin for sixteen years and didn't feel particularly different on or off of it. This year I had to switch to a new medication and I suspect it's not working, but I feel about the same so I'm not sure. Help!