I can hear that you are suffering and I want you to know that you can get over this because the love that you are feeling for this man is not healthy. I say this for several reasons. First, he doesn't love you. He is using you. This is hard to hear but you need to hear it. When you are in a very unhealthy relationship, it can feel good on the surface but deep down, it really is not meeting your needs. He is selfish, does not have integrity (he’s cheating on his wife and children) and he doesn’t care enough about his family or you to be faithful to either one. So my question is, why do you love someone who is like this?
The answer, I believe, is that you are not respecting yourself. You are settling for something that isn’t a real, honest love and you are settling for something that only hurts you (and his family.) So the question is, why do you feel that you aren’t worth more than this? Could it be that you have become involved with someone who is bad for you as a way of punishing yourself? Could you be involved with him because you know that you can never fully have him to yourself?
Here’s what I recommend. Stop punishing yourself and break up with him immediately. Your obsession with him doesn’t come from healthy love- it comes from somewhere else and it makes you feel “good” for now but it will tear your heart out. So, send him an email (don’t see him face to face because you will change your mind) and tell him that your relationship is over. Cut this off immediately. Living in this relationship is keeping torture alive.
Then, cry your heart out and get over him. Find someone (a good friend or counselor) you trust to help you understand why you are so cruel to yourself that you would be attracted to someone of poor character. And he does have bad character if he’s cheating. Ask God to help you find someone who is genuinely good for you, devoted to you and faithful to you. This is the only way to get over this pain. You deserve real healthy love but you will never find it as long as you stay in this bad relationship.