Lord almighty this is a tough spot. I'm so sorry. No one is on the DB forums because things are peachy, yet this is very sad. I don't mean to make it worse, only validate that your 31 years together are so precious, even if they were volatile at times.
I'm not sure you have much of a choice. If he's non-responsive then it really limits your options. You can't force him to communicate. The only question is how many unanswered messages you want to send to him.
What I WOULD recommend is a DB coach. They might guide you into a specific course of action that may not be mainstream (such as writing him a letter that addresses the core of your faults in the M without pursuit, judgment, or expectation), or other tools they have. Most people skim over this, but truly the DB coaches have seen these situations literally thousands of times and know what works and what doesn't in practice, not just theory.
Beyond that I'd recommend reading Cadet's links and of course DB/DR. No quick fixes, and you will need to detach and really learn to rebuild your own life while your H takes his journey.
Keep posting, and it would probably be good to talk to your marital history a bit. Hang in.
Me:38 XW:38 T:11 years M:8 years Kids: S14, D11, D7 BD/Move out day: 6/17/14, D final Dec 15