I should never have told her I like her?

I am in my mid-20's, and I recently told this girl that I had feelings for her and I liked her, but she didn't like me. I only told her this because I was acting weird around her, and it kind of scared her. So for some ******* reason I had this brilliant idea that if I just told her how I felt about her, everything would be fine. Biggest mistake ever because she didn't feel the same way, and now she hates me and never wants to talk to me ever. I even wrote her a letter about trying to explain to her my feelings and apologizing for the way I acted around her, and I guess it just made everything worst. She ended up betraying me and stabbing me in the back with my own letter by reporting me, and I got thrown out of cl for it. They basically said that I ually harred her. I had no idea telling someone you like them is ual harrment. The thing is, is that I shouldn't even have feelings or like this girl because she is younger (20 yrs old) and she has a kid, so that means she was promiscuous when she was a teen. I normally don't like or are attracted to girls who have kids. This has never happened to me ever. But for some reason I was so drawn to this girl. I literally couldn't help it. I don't even know how it happened. It just gradually happened. One day I don't have feelings and the next day I had this crush on her and it's been growing since. THIS IS ******* CRAZY!!! So I finally ******* told her, and basically she had no reaction, no emotion, told me she would see me next week, and said bye. I've been trying to get over this **** for the last couple of weeks. I kind of got over it for a while because it made me upset that she betrayed me and backstabbed me like that, but now I'm starting to think about her again. Why would I still think about someone who did this to me!!! I am so down, so broken, so tired, so lonely... Am I this desperate to have someone in my life that I would fall for a girl who clearly was not good for me.