If you have been the victim of a bad break up keep in mind that you need to let yourself feel the pain of the situation. It's the best thing you can do for yourself not to mention the first step in learning to heal. Do not ignore how you are feeling. You are probably feeling things yiou haven't ever felt before and the feelings will change every day. If you ignore your feelings and pretend that everything is fine then you are only lying to yourself.
Do not worry about what your ex is doing, it doesn't matter. You just need to concentrate on yourself, especially after a bad break up. You may not feel like it but you should research online healthy ways to handle what you are feeling.
Getting over your ex will take some time. So, take your time to figure things out. After a while you will find that you hardly think about your ex any more. Make the time constructive and treat yourself to a makeover or to find a new hobby. Everyone has something they have always wanted to do, now is the time to do it. You will be well on your way to regaining a healthy state of mind.
Feel your pain, but put a time limit on it. Two weeks to a month should do it. Stay away from your ex and do not try to contact them. This will only be detrimental to your recovery. Another good idea is to read a self help book to regain some self esteem that was lost due to the break up.
If, after a while you still can't seem to get past the broken relationship, find a counselor to talk to. Someone who is neutral is best to help you get through this terrible time in your life. A good counselor can teach you techniques to use to ease your pain and start to be healthy again.
Sooner or later you will start to feel human again and find you are even able to laugh and feel happiness. I know you do not feel like it now but you will. I guarantee it.
Years ago I learned a technique that I am going to share with you now. It will seem silly at first but it is incredibly healing. First, go buy some marshmallows. Keep them someplace safe and the next time you feel the anger bubble to the top get them from the cupboard and open the bag. Take one out and throw them, one at a time, as hard as you can into the kitchen sink. As you throw each just let everything out. Yell as loud as you can. When you are done, I bet you won't be angry any more. You might even be laughing.
If you can laugh, you know you can handle just about anything life can hand you. You will survive a bad break up and realize that you are probably better off without your ex anyway.