Pots & Sex life

Hi! Okay so i’m 16 years old & i have POTS or postural orthostatic tachycardia syndrome. If you don’t know what that is, it’s basically a chronic illness that messes up your autonomic nervous system (which is inside your body and is the thing that does everything in your body automatically, like breathing, digestion, movement, etc.). I’ve had symptoms and all of POTS since i was in 5th grade, so about 7 years? Anyways, just recently i started having sex (of course i use protection & i’m on birth control!), but i can never reach orgasm. I’m not sure if it’s just because that partner couldn’t please me enough or what, but all that happened was that it’d feel good for a while but i’d get bored of it & light headed. I’ve also just tried masturbating by myself and i’ve never reached that point either. I’m not sure if it’s because of POTS, or just me being young, but if anyone has any tips on why this happens and what i can do to change it please let me know! :))