Have you gone to see a psychologist? Regardless of where you stand in your marriage, you need to get some help for yourself. Staying in a marriage for your child kind of takes second place to staying in this world for your child. I'm not sure if you're looking for marital advice, or not, but the bottom line is that until you get help for yourself and stabilize your own emotions, nothing else is going to work. Please, if not for your own sake, for the sake of your child, go get some help.