For me a lot of the worries turned out to be just that, worries. When I finally told my XAH I wanted to leave there was no screaming or fight and he agreed with me it was best - I did not expect that. He actually acted amicably (and still is) which I also didn't expect - he was very easy about dividing what was mine versus his and it was fair. It was weird, it all just sort of fell in place. I went through a lot of emotions (sadness, fear of being alone) but my worries just sort of fell off. It was hard actually having him react the way he did because then the emotions of "he doesn't care" came up - but I worked through that (likely it's the disease talking anyway)...plus I can't control his reaction. I guess overall, the universe stepped in once I took my action.
What I like to do is think of the worst case...so one of my worries was the XAH would not pay the rent on the lease I was still on with him...so I thought about it and first of all he has too much pride not to pay and second of all if he didn't pay I would find out from the landlord and make arrangements to pay. That didn't happen but thinking it through like that helped me.
All in all it's step 1: I am powerless over alcohol, I am powerless over the person drinking the alcohol, I am powerless over the people and things surrounding the person drinking the alcohol, I am powerless over the people around that and all people, places and things. Once that really hit me it was a huge relief for me and I realized I could do it.
What happened for me was I decided all of those worst things I worried about, even if they happened, were not as bad as staying in an unhappy marriage.