This man is filling a void in your life, and while he is meeting that strong need, he will always have some degree of power over you.
I would suggest that, in order to move on, you try and identify exactly what you personally get from this man. Why do you want him? How does your relationship with him fulfil you? Be specific and detailed in your reply to yourself. Then consider what sort of things you could do to make yourself happy instead of sabotaging your life by going back to see him.
The flipside of this exercise is to write down everything negative you can think of about him. Be realistic. Look at the real person, not your ideal fantasy version of him. Find fault as much as possible. When you start avoiding him, record your resolve and your reasons for ending the relationship. That way, as time goes and you begin to crave him, you will be able to read over your notes. They will remind you of why you are not going to continue the harmful cycle of leaving him only to return and start all over again.
Most of all, know that your love is a precious gift and it is time to give it to someone who is worthy of you. You deserve so much better from life than someone who is unavailable to love you back. Once you stop focusing on him and open your eyes to opportunities, you might be pleasantly surprised.