How do I short my autism and social anxiety?

Anxiety is not the problem with autism. It's the part where you subconsciously give off "wrong" cues with your body language and speech that set people off. All the drugs do is make you disregard the fact that you're making people around you uncomfortable.

"One's biggest fear is a man with nothing to lose". Depression is indeed a very powerful motivator for some, for others it can lead to a downward spiral where at the end you either kill yourself or go 100%

First: start appreciating yourself, you're unique and a product of love.
Second: practice. Do a social faceplant and learn from it.
Third: believe in yourself and keep on being yourself. Nobody can imitate you.

long half life, one dose should be felt the next day too. 3rd day no effects but also no anxiety

I think you better long that, user.

Just communicate it
"Im feeling weird, because..."
See who relates
Your issues are probably much more common than you think