There's a reason you can't accept it. Listen to that voice. Respect your feelings.
As someone who's 23 year relationship ended after an affair I can tell you that fear keeps relationships like this going. Fear of the relationship ending. I had known my ex for much longer than 23 years - since we were 21. He was everything to me. The ending of that relationship was the hardest thing I have ever had to endure. I wanted to save it - he decided he didn't eventually.
3 years on I can now see we should have ended it sooner. That living like a half person trying to keep something afloat that is done is far worse thing. And I will never let ANYONE make me feel bad about myself again. The quiet power in that is wonderful.
I'm going to be frank here. Your relationship is over and you need to accept it. Your husband is being a coward and treating you shamefully. It's eating your dignity. It's fear of the unknown and co-dependance that is keeping you stuck. All I can say is it will be okay and you will find a better relationship, but not with someone else - with yourself. In the end that's all we have - ourselves.
Get a good counsellor for yourself NOW - shop around - people don't realise you should do this with therapists, if you have money - pay. I've had 4 great ones and 5 rubbish ones (which I left after a few sessions in all cases) over the course of my life.
Cut the drink etc. My break-up prop was smoking. Packed that in eventually.
Next time you feel in despair, remember this:
The way out is through the door.