Am I really that bad?

I find myself angry a lot because I can't seem to come in contact with a decent man.  I wonder is it the way I look or is it because I don't smile or what?  I can't seem to figure out the connection between the too.  I just seem to attract men that cheat on me , want me to be their mother and who don't work.  Can someone tell me what is wrong with that picture.  My best friend told me once that I'm not approachable, and men are intimidated by me.  I think that maybe true to a certain point but I'm not getting it at all.  I just want to know what the deal is where is all the good men?  I know there are some out there because I have met a few but they were either married or involved with someone else.  It's hard out putting yourself out there and it becomes even harder for me because of the trust.  I guess I shouldn't be that way but I can't help it, I know I shouldn't blame one man for another mistakes but it happens.  I just wish I knew what I could do different in order to come in contact with someone I can connect with.  I know for one that I'm afraid to fall in love or even like a man because of my past relationships I put a wall that  seems to be my distraction.  I know that one day someone will come and help me rebuild that but until then I'll just wait and continue to pray.