Please stop doubting yourself. Your soon-to-be-ex deceived you by hiding his drinking problem. Now he's saying "I want to be selfish." He's told you who he is, and it's just something that has to be accepted, even though it sucks.
Try to look at it this way: is it possible that you're romanticizing him now that he's moved out? Do you really want to risk coming home to another disaster? Is it worth it to try to work things out with someone who openly refuses to make an equal effort?
Being twice divorced doesn't make you a pariah. What it does make you is someone who will know in the future, after all of this is long past, to proceed with caution. And that's not a bad thing.
Revel in your time off, try to eat (in small doses, if that makes it easier), love your dog, and watch a lot of movies. Cry whenever you want to. Read a dumb book. Someday not too far from now you will be fine. What seems impossible to achieve emotionally at the moment will come to pass. Break down your days into small increments, as in, "What do I need to do to get through the next 15 minutes?" If the answer is "sleep," that's okay.
Oh, and go to a spa. Get your head rubbed, and all your nails painted. Then take your nice dog to a great park and eat a pizza with her/him in the car.