You have asked a loaded question there, whether you should leave or not. I think that's up to you to decide, on your own.
I think the answer to that will become clearer as you read here, and get responses also.
So I would do some reading and keep talking here.
First off, I want to say that you sound like you have a sound mind. I think you could use to hear that. You are not imagining things and you see his reality for what it is.
I think you can empower yourself right away on one thing that jumped out at me--his wanting attention in the evenings when he is drunk or on his way there--you have the right, and the power, to simply say--"Not when you are intoxicated".
This goes for conversations, physical desire, and anything else you want to throw in there.
You have the right to enforce that boundary. He will try to break it. You can simply walk away and refuse to engage, and tell him once again that you are not wavering on that rule you have made.
He can dislike it, and will. Too bad for him.
The message will be clear. Do not try to engage me in any way while you are intoxicated.
This is so that you aren't dragged into his crazy alcoholic thinking. He can do that alone, engage himself in his madness.
Rejection while drunk.
Who would consider that unreasonable?
Only a drunk.
It makes him look at himself whether he wants to or not.
Keep telling us those kinds of things that happen. You will learn how to empower yourself, and eventually, decide what you want to do overall.