The common denominator is YOUR LOW SELF ESTEEM. That is fixable. You need to believe in yourself more.
You sound like a truly caring, intelligent and articulate woman, anyone would be LUCKY to have you. Bollocks to anyone that can't see that!
You need to ask more of life for yourself, you deserve it.
End the thing, go on the super dooper christmas thingy and treat yourself in all ways possible, get used to caring for yourself and then that is what you will expect of others.
I found that when I dumped the bloke I was seeing, the one that I had to call the cops on.... yes him.
When I realised that I could see odd ball, or not good enough and that I had the right to end the relationship. Doing that gave me so much power back.
the next date I went out with was a revelation, I was cool, calm and not a hint of nerves. The lack of me worrying if I was good enough for him meant that I had like a force field that protected me against all those that would try to control me or have some kind of power agenda with me in mind.
Recovery from dysfunctional relationships has no short cuts, you have to do it all in steps.
This is probably your last hurdle. When you are ready, you will meet Ms Right. This woman you are seeing, is better than the last one, and better than the nutter it took you so much effort to free yourself from.
The next one will be even better.
I am loved up atm, I've been with a wonderful guy for 7m. I hope he's the one, but I know that if it doesn't work out, there is a reason and that the next guy will be even better. So I'm not going to cling. I trust what is coming my way, cos I know I have the strength to navigate myself away from harm.