Butterfly - You sound a bit better and I hope you are.
its strange to me that on this side of the fence we often support and encourage no contact - then we see it happen on the other side its attributed to that person being an A - and we damn them for their actions.
I'm going to take the alcohol out of the picture because I think it confuses rather than explains how I see this situation. As you have described your marriage has been an uphill battle most of the time or at least for a very significant period of time. I don't think either of you brought out the best in each other regardless of whether you love each other. Good people can be no good for each other (and here I will say adding addiction in is just another level of "no good") Relationships and their interactions are habitual. Its very hard to break the cycle and sometimes the only way to do that is to go no contact. If your husband was still in contact with you regularly you will still be on the merry go round. Drama, Chaos, On again off again, Together then split etc.....you know the drill.
I am unsure if this is the reason your husband has gone no contact or if he really has because of the alcohol. What I do know is his no contact is a gift to you for whatever reason it happened.
It gets easier when you accept it as has been pointed out. It also gets easier when you stop trying to figure out what happened. I think what happened is it wasn't working. You both have tried to make it work and it still wasn't working - for years. I doubt there would have been anything YOU could have done or that HE could have done. You each are who you are.
A metaphor to this is a recent a event for a friend of a friend. His adult son went missing. He was last seen at 4 am by his girlfriend in January getting out of bed not feeling well. He disappeared with no clues whatsoever - car, keys, phone everything left at the house. A massive search took place and they came up with nothing. About a month to the day he was found drowned in the the lake near his house. There has been no rock unturned to try and figure out what happened - how did he get up coughing at 4 am and end up drowned a mile from his house? I don't know that they will ever know - maybe one day they will, but the bottom line is their son is gone and no matter how it happened it doesn't change the outcome.
Your husband has given you reasons why he divorced. Whether there is more to it or his explanation is accurate it doesn't change anything. What I think will happen to you as you get further away from it is that you will see more clearly that you weren't happy the vast majority of the time. That you lived full of anxiety and doubt. And that no matter what you would have or could have done to "change" yourself it would have ended up the same.
The day will come when you don't care. I promise it will as you move forward in accepting the situation and going on with life.
Hoping today is a great day for you Butterfly and (((hugs))).