Dennis,
I think it would be best for YOU to be honest with her. Tell her how much you love her and how sorry you are that you didn't recognize your need for help sooner. Also, acknowledge that living apart is probably what is best until you get the help you need. But that you hope one day to be the husband she deserves. Perhaps she'll hear you. Perhaps she won't. Either way, I think you will feel better knowing you told her how you feel.
The day you recognize (REALLY, REALLY RECOGNIZE) that you have ptsd is an awakening. It will take work on your part, Dennis, but things can get a lot better. And it is worth it.
I hope it is okay to say that I am praying for you and for your wife.