(...) nagging never helps. Begging and pleading don't seem to work either. I just hope that something will trigger your husband to get help.
Nagging anyone about anything usually = an immediate 'if you are going to be an unstoppable force, I am going to be an immovable object' effect, as far as I have seen. Definitely not a winner. Agreed.
What I found worked with respect to getting my sufferer into therapy (for a little bit at least), was working on his fear that his mind was not a legitimate thing to be 'broken,' and that he should just suck it up and deal.
I asked him very reasonably; if his rifle were jammed or his truck not starting, or his vest faulty, or his radio broken, he would fix it, right? And if it were something beyond his ability to fix, he would give it to someone who could fix it for him, right? Would he go into combat with broken equipment? No? His mind is his most complicated and necessary piece of equipment; if it is not operating correctly, it needs to be fixed to the best of its capability. It can get broken in combat, the same as everything else. And anyone who thinks he is weak for fixing a broken radio or truck is clearly crazy, right? So anyone who gets on his case for wanting to tune up his head can go and (redacted).
Your mileage may vary, of course, but sometimes it helps to take a different tack.
Good luck, lady. I hope he manages to let himself realize it's better for you guys if he gets some help.