While I don't have the words to say to make things better, or any advice (seems like I'm always short in these two areas), I can understand your pain and frustration. It really is very sad, but at the same time, you know this is the only way for you at this time.
At some point, I believe your SO will come to his senses and realize what he has done. The only hope at that point is that he become serious enough about his own issues to try and work through them before seeking to rectify things with you. I applaud you for your strength through all this.
Please keep us up to date and let us know how you're doing in the coming weeks.
Rob
"Achieve success, but without vanity; Achieve success, but without aggression; Achieve success, but without gain; Achieve success, but without force." Lao Tzu