Most, if not all navy bases have free mental health counselors for service members and their family members. They offer a variety of counseling from marriage, post deployment, PTSD supporters, etc. I can't remember the name of the office, and wouldn't be surprised if the name changed anyways. It should be in the base phone book, or ask the Chaplin's office for the #.
You might ask your husband to at least try counseling before any final decisions are made. Even if it's just couples counseling, not PTSD counseling which he may be resistant to. I have no idea from your post what you have tried already. Even if he decides not to attend, you can receive counseling to help you cope with what ever happens.
Most bases also have support groups for various things - spouses of deployed members, spouses of members with PTSD, etc. That may also provide some support for you as you go through this difficult process. Once again the Chaplain's office should have the #'s.
I'm not a big fan of military religious personnel (people who work as chaplains, or for the chaplains (long irrelevant story)), but their office is the center of the spider web of support for military members and their families.