How to handle alcoholic husbands demands and ultimatums?

I am currently separated from my husband, he is an alcoholic. We are trying to make steps to restore our marriage. He makes demands and ultimatums and we are in this constant back and forth cycle. He will bust out his Manual on me, make a demand (latest one was that I need to quit SCS), I say “I love you but I am not going to do that”, then his ultimatum/threat is “then we are divorcing”. Then the next day he comes back and changes his tune telling me he loves me and wants this to work and the cycle starts all over again. Being an alcoholic in denial that he’s got a problem exacerbates this situation. From my perspective, his brain is simply not functioning properly as long as he chooses to continue to drink. I need to find my part in this cycle. I’m trying to love him through this. I’m thinking I need to cut off all contact until he gets help and stops drinking altogether. And I will have to accept that it may mean my marriage is going to be over.