I'm very sorry to hear about the pain you had in your childhood and about what you're going through now. All humans are drawn to people who are like our parents, and in our cases, that means to people who abuse drinking. I can't tell you what to do, and I really don't give advice around here because I am so young and new to healing myself. I'm not entirely sure whether your boyfriend simply drinks for fun, like many people his (and my) age do, or if he is actually an alcoholic. I think it would be wise to find out because there is a difference.
I've yet to really be in your situation, but I do know that I personally will never be able to have a relationship with an alcoholic. It would be far too painful for me and I don't think I could ever heal. I guess some people do have... healthy relationships with alcoholic partners though.