'Ex' means the relationship is over so you should be moving on in your life and not be so concerned that your ex is angry with you. If you broke up with your ex then of course he is going to be hurt...
First, talk with them to make sure your anger is valid; it may have been a misunderstanding that can be cleared up. If it is valid, and you want them back, try therapy; talking it out with a mutual...
You do not deal with an angry boyfriend. You must leave angry people out of your life if you want to have peace. An angry person is not a good person. There are many people in this world worthy of...