Stimulants make you better than baseline on some tasks, but definitely not all of them, and not all creative ones. (Especially if you lose out on sleep or your teeth start falling out from abusing them.)

It's usually pretty obvious if you have ADD, and it's not "you're bad at your job", it's more like "everything outside your job is falling apart". Your job provides enough stress to concentrate on it most of the time.

Adderall also doesn't make you "more stimulated" like caffeine does - a regular psychiatric dose should make you a little calmer, since your life isn't falling apart anymore.