Does alcohol help to cure or reduce ulcer or aggravates it. Otherwise what is the best treatment or prevention for it. Thanks?

Stop alcohol. Alcohol would not help an ulcer, and may even aggravate it. You should see a doctor and possibly have a scope put down to see the ulcer and take a little sample of it to make sure it isn't a cancer. If it's a simple ulcer it will need some powerful acid reducing medication and a review of your diet. I hope that's helpful.