Alcohol Tolerance

Im 18 male, 5’8 and 134lbs. I first got drunk at 13, and until now I was easily able to hold a lot of booze down. Im talking about over 15 shots of pure vodka and then some. I was able to combine alcohol and after drinking a lot and I mean a lot of alcohol (past the point of blacking out) I only had to deal with a slight headache and a bit of nausea.

However, this past year I started throwing up once when drinking, but still easy hangovers. After a few months, I was throwing up multiple times but still getting drunk. A few months ago I threw up 3 times while drinking and once the next morning. This week I had only 2 glasses of whiskey cola and threw up 7 times with bad headaches and digestive problems. Two nights ago I had 2-3 shots of gin and Im still hungover and extremely nauseous, even after throwing up.

I have autism and the only way I can get dancing and talking at parties is through alcohol. Even one sip makes me throw up and leaves me hungover.

I am scared and I haven’t really found anyone that deals with this. What could be the reason??