How Much Is Too Much?

I have been with my husband 16 years. 14 years have been as an Army spouse. We've been through 8 deployments and have 4 kids. My husband has become progressively worse with each deployment. This last one was really rough and combined with a longer than usual time at home (1 year) the depth of his problems have become apparently clear. My children are suffering, our family is suffering and most importantly he is suffering alone in his head and refuses to do anything about it even though he has accepted the problem. I have reached the end of my rope with the breaking point being my birthday 2 March. I am at the point where I am weighing the horrible guilt I feel for what he has to be going though and the guilt of staying with a man my children are beginning to despise. His angry outbursts, unemotional slights towards everyone, alcohol abuse, and insensitive behaviors have gotten to be too much to handle. I'm now faced with the question..when is it enough. When do you leave a mature man alone to face the down--range demons he clearly can't handle in order to save your children and yourself from living through trauma because of it?