In any relationship there are mistakes made by all involved. Sometimes one is more guilty of mistakes than the other.
If you are breaking up, it's good to get yourself in the best shape you can and not worry too much about who's at fault. You can waste a lot of energy on things that just don't matter in the context of the rest of your life, starting today. Get your fair settlement. Get a therapist or support group. Move on. Over the years, you will have plenty of time to reflect on the who's, how's, why's and what if's.