Painfully lonely

I have an unbelievable low amount of self esteem. I was in a marriage for 17 years because I was just too fearful of being alone. It is paralyzing at times. I find myself in so many "dating" sites just so someone will pay attention to me. There are plenty of men willing to sleep with me, and I go. Not with every single one, but enough to know it's not a good life choice. In the moment, I feel good because I am wanted, even if it is fake. After, I feel horrible and find myself trying to get these men to sleep with me again or look for someone who will. When nobody responds, it's unbearable at times. I just don't have anyone to talk to and needed to get it off my chest.