Mojo
I can see quite a bit of my H in you and your H pre-separation. It was basically impossible for him to see himself being happy if he stayed in the M. We were too enmeshed. The thought of being differentiated and STILL be M to each other was inconceivable. S seemed like the only way out of that mess. Maybe it was for a while. But I don't think it absolutely had to be. If both of us were able to gain a new perspective, we might have been able to accomplish it without the mess of S.
But that is the hard part isn't it. Gaining a new perspective. Much easier when both people change, not just one. But like you said, you should be able to express/assert yourself in the M so that you as an Individual can still thrive even if the R is not where you want it to be.
When both the M and the Individual are a mess, that leads to big problems. People tend to want to escape the M thinking that is the problem, when really the problem more likely lies in the two individual people. Fix the people and the M can survive as well as thrive.
And not that we are ever "fixed", it's just a constant work in progress.