We don't have much control over our dreams . Most of the times dreams don't make much sense. So it is always better to just neglect your dreams and not take them seriously. We should not worry too much about the things we can't control. So it is better that you don't create this dialogue with yourself about why you have dreams about him etc. You will have to think if that guy is only in your dreams or he is frequent part of your thinking. If you think about him even when you are awake then I think you should consult a psychologist,counsellor or a psychiatrist.

Speak to a counsellor to help you overcome your problem. Addressing your feelings & accepting them can help you move on in your life.