Upside,
Luckily for you, you have such a good understanding of what's going on and what you need to do. You have no control over H, only yourself.

I haven't even gotten nearly as close to where you are, but I do feel that now is time for me to move on without H as well. I feel completely defeated, having done all the damage control I could possibly do over the past 3+ years.

Look on the bright side though - I'd rather be in our shoes than in theirs.