Looking for insight with people with Autism and Sensory

Just to say this, I have both of these but need other people to tell me. This is mostly to do with alcohol. When I have a small drink, let's just 12oz at 7% I get instantly light headed and or almost fall asleep/pass out. Almost like I've slipped something. It happens when I've had enough water or with a big meal. I have a theory that maybe it could be because of sensory or autism, or even both. To add some more I have almost the same reaction with caffeine, but not to that degree. My sister has the same condition so I'm waiting for her to be able to drink to see if her reaction is the same as mine.