Break Up

2 nights ago I broke off a 3 year relationship with a married man. I am an intelligent, educated, fairly attractive woman who should know better than to get into this type of relationship but I did it after believing what turned out to be the world's best liar. I went to high school with this man and we were friends then but not close. He found me on Facebook and we started emailing and met for lunch when I was in his town 2 months later. There was instant wild chemistry between us and he told me he was getting out of his marriage of only 1 year. Here it is 3 years later and the excuses and reasons that he can't quite "do it yet" are endless and quite tiresome at this point. We ended it and of course, I am devastated since this is really the first man I have truly completely and unconditionally loved. I have been married twice before. My first husband cheated on me after 10 years of marriage and the second one just didn't work out after 3. We are still good friends. I have had one other long term relationship with a married man and one with a man who was always seeing other women on the side. Am I just crazy or stupid or what?? I began seeing a therapist a few months ago and she has helped but it is hard to try and regain your self esteem and identity after this situation. I got on here just trying to see if there are others that fell for a load of bull like I did. This breakup is the hardest thing I've ever had to deal with in my 57 years. I feel like such a loser.