Hon,
Alcoholics love enablers, people who want to help. Alcoholics can only count on one person to get sober, and that's himself. I was 34 years with axh, and if I knew what you just told me early in my relationship, I would run fast and never look back.
Pain and more pain is what it is like having a relationship with an addict. Tell him you love him and you are stepping away so he can "regroup" on his sobriety. No relationship is good when he needs to focus on himself, 100%. If he wants a time frame tell him to reach out at his 6 month alcohol free anniversary date to check in. They say it is hard to get rid of an addict, so it might not be that easy, be prepared. Hugs, you will be so grateful you did this for yourself, when you look back.