Adderall®, Concerta®, Dexedrine®, Focalin®, Metadate®, Methylin®, Ritalin® are all “brand name” amphetamines.
Yup, and they're controlled substances that you can't buy without a prescription and which are only supplied in limited quantity. Your app branding is literally a kind of drug abuse - using a drug to stay awake rather than its medical use to just be normally functional.
This isn't to endorse Apple, which ought to apply its guidelines more consistently instead of ignoring or enforcing them in arbitrary manner, and which should be more transparent with communities of users rather than using its leverage against individual developers with no real process or recourse.
But when you get down to it, you are in violation of the ToS and there isn't a great moral crusade here. Rebrand and be happy.