I was determined to figure out "what was wrong with me". I was convinced there was some mysterious medical reason why I could not process alcohol. I think I felt like if I had a fancy diagnosis it would make it easier for me to not drink. Well....the reality is that I'm an alcoholic and that I've trashed my body to the point of it can't process alcohol anymore. It took a number of trips to the hospital as well as a significant car accident for me to FINALLY get it....I am an alcoholic, I cannot drink alcohol, I need help to not drink.
You don't need to figure out what is wrong with you if you simply stop drinking. If there isn't alcohol in your body, you won't get sick anymore. You already mentioned that you have additional medical issues. This is a no-brainer. I know that getting sober scares you and it seems drastic. Death is drastic. Stick around this site. You are WAY too young to put yourself through more trouble. This is a great place to get support and information!