If you're not sure, break up.

If you have to make a decision one way or the other on the marriage decision — she’s given you an ultimatum or put a pistol to your head — err to the side of breaking up. You can always get back together relatively cheaply (flowers, $60; dinner, $200; jewelry, $300; make-up sex, priceless), but getting divorced is a fuck-load more expensive.

Breaking Free : A Recovery Handbook for Facing Codependence.

If you’re questioning whether or not you love her or not, then you don’t. Dump her if you don’t love her. Dump her if you’re just fuck-buddies. Dump her if she annoys you. Dump her if you have to work too hard to be with her. And dump her if you fight too much.

But, dump her for in compatibility reasons, not commitment phobias. If you have irrational commitment issues, you’re unable to maintain a long-term relationship, or you have self-destructive tendencies, you need to get professional help. And the sooner, the better. Otherwise, when you find yourself old and alone, you’ll have no one to blame but your damn neurotic pussy self.