Can I point out that you just asked for "help"? (Picture me ducking, just in case you threw an imaginary object...or a real one?, at your computer screen.)
First, congratulations on getting out of the abusive relationship. Not an easy thing to do! If you look around on here, you'll find a lot of people describing what you're describing, in different degrees and for different reasons. You'll also find a lot of "relationship issues". Go back and reread your second paragraph. Step back a little and pretend someone else wrote it. How easy is it going to be to be in a relationship with that person? If someone you like came to you, looking for advice, with that paragraph, what would you tell them? Would you tell them "Hey, you're a worthless idiot who doesn't DESERVE a good relationship"? (I sincerely hope not!) Would you tell them, "The world is a rotten place and everything is someone else's fault!"? (I hope not again!) What WOULD you tell them?
I'll tell you a version of what my therapist told me, the first time I emailed him. "PTSD is a big deal. It affects more aspects of your life than you know, and it won't go away by itself." Then he said he just happened to have an opening, that very week, just in case I wanted to come in and talk. He's a smart guy. Without even knowing me, he knew I'd have stalled, "minimized", and made excuses right up to the point where I picked a more drastic way to solve my problems than sending him an email. I'm glad I made the appointment and kept it. (BTW, walking through that door the first time was one of the hardest things I've ever done. So was the following week. It DOES get easier, but I still spend a fair amount of time trying to talk myself out of going. In some ways, I think just showing up is a victory.)
I'll recommend a great book, "Once a Warrior, Always a Warrior." Maybe you can get it at your local library. You can get it online, even a used copy, reasonably priced. When I first started dealing with this stuff, my therapist was occasionally annoying and frustrating because he has what seems (to me) to be kind of a fluffy, New Agey way of explaining stuff. I'd hear something he said or read something he wrote and be left thinking "What the heck was THAT supposed to be???" This book is great! The author takes the approach "This is what you might be experiencing. This is the reason. Here's some ideas on what you can do," It also includes some stories of other people's experiences that were eye opening.
As far as the relationship thing goes....I'm not in much of a position to talk. I've been in a few, all but one were train wrecks. Was it all my fault? No, it appears I somehow attract people like your ex GF. Interesting, huh? I haven't quite figured out the reason yet (bigger fish that need frying first, I guess) but I'm totally sure there's a reason. I've decided I'd better sort out what that reason is BEFORE I take another shot at a relationship. Meanwhile, good luck and welcome aboard.