dear Brett, thanks for posting on here as well as Justinok, it does take courage for doing this for the first time, as a lot of people decide whether or not to do it, but it's good that you have.
It seems as though there are a couple of issues here, one that your parents who would probably be in their 60's, accept their son, but don't accept being gay, and the other problem is that your partner has a drinking problem which leads him to be aggressive.
Firstly you don't approve of his drinking so this is going to lead to problems between the both of you, eventually, so I wonder whether he has any inclination of wanting to cut down, or is he using this as an escape from being rejected by your parents.
People who are in their later years of life find it difficult to accept same sex relationships, but they have to understand that you aren't going to change, that's the way you want to be, and there's no problem with this, maybe they know of his drinking and becoming aggressive, which you can let us know. Geoff.