Welcome Marie.
The only advice I can really give on your current situation is from the opposite side of the coin. I was the alcoholic boyfriend. Two relationships I had in my early through mid twenties crashed and burned pretty bad because of my drinking. Both of these women tried to 'fix' me, or 'cure' my alcoholism. This is something that I don't think can be done until the alcoholic has become disgusted with his/her self enough to WANT to stop. What most people call hitting 'bottom'. You are not his nurse or caretaker, you are his girlfriend.
I wish you luck and there are some really good people here you can talk with when everything seems overwhelming.