As it seems I am want to do, these days... I too have a PS (lol):
Remember... if your H is MLC, chances are he's not coming out the other side the man you remembered... maybe some of the good parts will be there, but there will be other parts you don't know and may not like, of course, there could also be better parts, too...
The point is, if you somehow save your M, you could possibly be M to the man your H currently is...
So, do you want to take that chance, or do you want to get moving forward in a positive direction for your future... and if your H changes his mind, you can get to know him again and see if he's someone you want to be in a R with?
Or are you prepared to risk remaining in a M with a man you don't really know and maybe don't even really like...?
That doesn't mean you file D... It just means you move forward...