No one's perfect, this is true, but it sounds like you've gotten involved with a real nutjob here, from what you've said. This person needs to grow up before she ever gets involved in a serious relationship. And not to be mean-spirited, but always remember...dogs are faithful too.
You yourself sound like you have some self-esteem issues. So, knowing this, I'd say that you too should be on your own for awhile, do some growing up and soul-searching, and get to know yourself better as a person before you attempt to involve yourself with anyone else. There are plenty of good people left in the world, they're just not easy to find because all the shitheads jump out at you and say "LOOK AT ME!". But trust me...they're out there. My wife's one of them, if I could clone her and send you a copy then I would. :D
Personally, I disowned my family years ago and it was the best move I ever made. Furthermore, I needed that time alone...REALLY alone...to get my shit together. Sounds like you could use the same. A major part of self-esteem problems is justifying the downfalls of others who you are attached to...you exhibit this pretty clearly (as I did as well). So take it from someone who's been there and done that...terminate this relationship and be single, don't look for another until you do some personal growth of your own. In fact, don't look at all...it will come to you when the time is right. And above all, NEVER SETTLE FOR SECOND BEST. You're worth more than that.
That's all the time we have for today. Please stop by the receptionist's office on your way out and drop off the check.