OP, I'm sorry about all of your bad experiences with men. That said, I think any of us can relate to being just sick and tired of dating and relationships. I think having low self esteem exacerbates the situation as it impaires your judgement but I commend you on sharing that with us because something like that is very personal.
I really wish I could say it will get better, you will meet Mr. Right but I can't because I really don't know. It took me forever to meet the guy I'm currently with and believe me when I say I was on my last leg. I'm 35 and things are so different when you are in your 30's and dating. The quality is poor, the baggage is excessive and because you are a black woman, it will be more difficult. All I can do for you sista is give you a big ole hug and tell you to do you.
I only have one thing to say, it is not your fault that the guys just want to sleep with you. THe supposedly goods ones who change their minds about you and then say it is your fault, weher never good in the first place. That is manipulation and abuse. It is not your fault. Men who just want sex go for all types of women. It has nothing to do with you.
Wow, there's so much of this post I could have written myself, it's crazy.
I'm still dealing with a lot of these feelings so I don't think I'm in a position to be of much help, but just know that you're not alone.
I can totally relate. You are not alone in what u are feeling.
If I were you I'd find a therapist (to help me heal, understand patterns, and re-learn to think positively) and a dating coach (to help me with navigating the dating world). I think you just need a little help and support. I certainly wouldn't give up on getting married before getting outside help and support.
ETA: oops sorry I missed that you've already been in therapy. But I would still recommend that you go back. It sounds like you've made lots of progress, you just need a little more help.