I'm so sorry you're going through this. I don't have any words of wisdom to offer except to reinforce that it won't always hurt this much. Just focus on taking care of yourself and plan some fun activities or a holiday to give yourself something to look forward to. It may seem like he has it all right now but karma always comes calling and his selfish ways will catch up with him. In a few years time things will look very different for both of you I'm sure.