There are lots of people out there who love nothing better than to piss in other people's cornflakes.
Life is too short to allow people like that affect you or your life.
Case in point:
The company that employs me went through several rounds of lay-offs since November.
For months, a number of people have been telling me that I was "on the list".
I simply kept working on the project that I was assigned.
After all was said and done, I had a chat with the corporate VP, who told me that I was never on any sort of list.
This kind of thing has happened to me more than once...and yet I'm still employed here.
Sounds like your ex-GF has some chronic self-esteem issues that sound pretty serious.
You're not going to be able to fix her, she must want to do that for herself.
One thing I have learned is that a woman can really make or break a man.
Miss "right" can potentially help to propel a man to greatness...the wrong one can virtually destroy him.
Best advice I can give is to keep working towards creating your own little fiefdom and living as best you can (which is pretty much what I am doing).
Sooner or later the right person is going to come along...but I wouldn't make that a high priority.
Worry more about yourself first.
Sounds like you're about due for some recoil therapy...