Hang in there Hopefloats. He is in a bad place, but he CAN get better. And you are not even remotely alone in dealing with this....
FWIW - when my H is bad he always says we are getting a divorce. But he doesn't do anything about it. Why? Because he does not even remotely want to divorce me. Obviously I don't know your husband, but if you guys don't have relationship issues that pre-date or are apart from the PTSD - my guess is that he's away from you to protect you. Remember, I don't know either of you and it's just a guess, but it is common enough that it is worth keeping in mind as a possibility.
There are also programs for family members of military with PTSD on most bases. Unfortunately they all seem to be named different things - but if you ask around - the local staff sergeant for any platoon that is currently deployed is not a bad place to start - the counseling folk usually make the rounds of the wives groups at the start of deployments. It helps not to be alone...