I hear you, and I'd like to respond.
I think it's good that you can put a number on the probability of your M's survival, but I caution that the number doesn't mean much. The fact is that your M is a specific M, and probabilities say very little about specific outcomes.
What counts, I think, is what you want. If you want R, then one key goal for the process is to be able to work for R while keeping yourself protected against further trauma, and you seem to be setting yourself up to do exactly that. That bodes well for you, and I think that's great! If your H steps up, R proceeds; if he doesn't, more pain is in store for you, but you sound prepared to weather that storm.
Being betrayed dumps immense pain on us BSes; we can't change that. We can, however, manage our recovery process more or less effectively. It sounds like you'll be on the 'more effective' side.
That's a small comfort, in many ways - but any help is wholly welcome.