Trouble is mate - she's milking you of all the energy and self respect that makes you attractive to other women, because she wants you all to herself even if she doesn't love you.
If you turfed her out and went away for a bit to clear your head, you'd have more of your own presence of mind to be able to handle the tantrums and mood swings.
I have a friend in what appears to be precisely the same situation, he loves her, he knows she's leeching everything from him, he knows they will never last in the long run.
But he can't help himself because it seems easier to put up with a miserable relationship, rather than to make the break and rediscover the person you were before you had to suffer all this mess.
I think you need to believe in yourself rather than to continue deluding yourself.
You could be so, so much happier six months from now.