My personal opinion is:
Don't sell yourself short. There is someone who will treat you as you should be treated and return the love that you have for him. I know it hurts and will be tough but please let this guy go. He is not good for you. I think he is someone who can't be alone so when he is done with his flings or they catch on and boot his butt he calls on you until the next one comes around. Seems like an endless repeatitive cycle.
You deserve so much more.
Big hugs and happy thoughts. You can do it. I did this after my divorce. I printed a label from a label maker that said, "I will survive" and stuck it on my rearview mirror.