What a load of drama. You can't wait for him; it is selfish of him to ask that. Don't let their toxic relationship become a part of your life. Move on. Date. Date many many people. Mourn the loss, but start creating your own life without them. Let it just be a friendship. Love is infinite, and you will find others to love, whether they are partnered, male, female, poly or not. Take the steps, walk away.
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein