While I admire how much you love and care about him I think you are not in a position to truly help. His acting out is hurtful and if the 8 years together wasn’t enough for him to find ways to talk to you, get help, and prevent this, then you will be living with the sword of Damocles hanging over you going forward.
I recommend you get some individual therapy (the find help tab at the top of this page will help you find someone in this area. Your first allegiance needs to be to yourself and your own well-being. He needs something more than you can provide, and the way you can help isn’t by talking to him, but by offering to help him find services for his bipolar condition. Helping him get help is the best way for you to have a connection without trying to make things better on your own. As you are helping him to find treatment option for no or low cost you can also point him toward our forums. They are free and offer a community of people who are struggling with similar issues.
Taking care of yourself isn’t a selfish act. It is important for you to deal with the emotional whiplash of what has just happened.
Wishing you patience and peace,
Proof Positive Blog @ PsychCentral