Hello,
Welcome to ehealthforum
I can understand what you might be going through but no one in this world is so much important especially one who cheated you that you think of dying for him.I know it is very easy to say but you have to be strong and determined as you have to come out of it.There are many other good people in this world and you deserve someone much better.
Try to involve yourself in other activities which you are fond of as music,movies,swimming.Spend time with your friends and family and do not be alone as you will ponder over the things.Go out and meet new people, world is so beautiful.Do some meditation/Yoga exercises which would help you in coming out.You can also visit a counsellor who can talk to you and listen carefully.
I really want you to come out and enjoy life.
Take care