I'm male. Am I better off doing without sex? I have antipsychotic related weight gain but nothing major. If Anyone likes I can pm a picture so you can judge my chances for achieving a hook-up, and how attractive she could be, and any advice on my appearance.
I think I'm lonely and would like a nice woman to have sex with.
I think you're taking a bit of a wrong approach here, you're most likely to just get ridiculed if you ask that from random strangers on the net... (sorry for pointing this out)
I have an autism spectrum disorder, too, and I need an antipsychotic medication to prevent stress-induced reactive psychoses. I had gained some extra weight at one point, too, but after quitting regular alcohol use, I quickly lost weight and returned to normal (or maybe even slightly underweight) BMI. I was as old as 26 when I got sex for the first time, and that was with a hooker (surprise, surprise...)
When you're an adult trying to look for a relationship, I don't think it's that important how you look like (as long as there's nothing really grotesque/pathological in your appearance), it's probably way more important to make a trustworthy and responsible impression. If you have a developmental or mental disorder, your best chance to find a girlfriend would probably be to go to some kind of self-help/support group where you get to know some other, including female, people who have similar problems. Or if you have some particular hobby, like yoga, art or something like that, you could go to some group related to that.
If it's simply sex what you're after, it may be most reasonable to just save some money for buying sex from a prostitute, like I did when I was about your age. (just remember to use protection)
Good luck, anyway!