I'm sorry for all the pain you're going through. I had a terrible breakup a while ago and I kept waking up in the middle of the night and I was so angry. The thing that helped me the most at those times was meditation. I never tried it before and I thought it was just new age bs, but it really helped. It took a lot of practice to actually be able to clear all the thoughts from my head and just focus on my breathing. But once you get it, it can be really calming. I can't exactly describe it, but it put me in a place where there was just me and my breathing and my heart beating and it made me feel very strong and like I could get though anything and just let everything go.
It might be worth a try.
Leah