Given your background and history dealing with an alcoholic, it's understandable that you are getting triggered by your bf's drinking. However, it doesn't seem like he is going overboard or like he's an alcoholic. So you have to determine whether you can put up with feeling triggered with intense reactions when he has a drink or two, i knowing that it comes from your history, or whether that is a dealbreaker for you and you need to be with someone who doesn't drink at all or trigger you in this way.