Why am I so lonely now?

I was lonely for a little while but then I started going out and just not caring and having fun. Eventually I met a woman at work and we hit it off for 7 months. However, she turned out to be abusive and damaged my self-esteem. I broke it off with her and it was very hard because the abuse didn't stop. Not only do I have a broken heart, but now i'm left doubting myself a lot and notice my confidence levels have plummeted after examining how I am before and after meeting her. Now I just want to get out of this funk. Half of me wants to go out and have fun, but the other half of me is so damaged and messed up from her tourment I don't know what to think. Not only that I keep thinking about her being with someone else, because I know how easy it is for her to go out. Now I'm just left in the dust, alone, all my friends are married and have women, so I do hang out with them, but it's hard. My family is going through drama and doesn't want to hear mine, so I really don't know what to do. I just want to bust free from this funk and get on with my life! And I tell myself that all the time, but why does it seem so tough sometimes?