I understand that feeling of how you've put so much into this - blood, sweat and tears and in the end, it all seems like you did it for nothing.
I'm at the opposite end of the spectrum from you because I WISH my ABF would leave ME after almost 15 years of this. A couple of years ago, I wouldn't have wanted that, but I know now that I'm ready to cut my losses and move on. It took me a long time to realize that there are worse things than being alone, and this is one of them. Whatever your fear is in losing him, it will help to concentrate on what you might be gaining.
From my perspective this is an opportunity for you, but you just can't see it yet, through the anger. You've gotten a lot of great suggestions here for helping to deal with that anger, and I hope you are able to use some of them. I just wanted you to know that IMO, you are very lucky to be given this opportunity - to finally get away from the insanity and to get yourself healthy. Think about doing all of those great things for YOURSELF, instead of for someone who expected them, yet likely wasn't even able to appreciate them.
Like someone here said - he's been running away from his relationship responsibilities since the beginning and now he's just found a new way to continue doing it. Sounds like he probably was never going to be emotionally available to you, no matter what, and as hard as that is to take, it doesn't have to be the end of your world. It could be the beginning of something new, more peaceful and perhaps even wonderful. I hope at some point you'll be able to get past that anger enough to look back and see this
