Like Jas said, give her the space she needs and don't try to smother her.
Although women may say otherwise, the reality is that deep down they do not want a man that smothers them and during a rocky time in the relationship, the best thing you can do is STEP AWAY and let your absence make her realize how much she actually does rely on you for support. That may be hard for you to do, but that is the only option you have if you REALLY want to keep her.
Now, if you back away and the relationship does end, you'll know that you guys were truly not supposed to be together and better that you figured it out now rather than after being married.