that really bites, man. we go through enough guilt and self-doubt without the people we trust most coming right out and TELLING us they don't accept us. my only advice is to never ever talk to your mom about this again. you just have to wait for it to blow over.
meanwhile, you should just tell yourself over and over again that you haven't done anything wrong, you're not a freak, you're a perfectly ordinary dude. comparing diaper wearing to underage drinking and drug use is just outrageous. you're probably a better kid than 90% of the kids your age, and yet she acts like it's the end of the world just because of a pack of diapers. she sounds like a very closed-minded person, and i think you've just got to accept that that's the way she is. i'm sure she loves you, and she's just trying to do what's best for you, but all she's doing is making you feel awful about yourself. be strong and don't let it get to you. you shouldn't have to feel awful about something you didn't ask for and can't control.