Hi Daisy,
when people arrive on this board in 95% of the cases at first the situation needs to be stabilized. Both sides need a better awareness of what they are responsible for aka. boundaries. Both sides need to learn to manage emotions better aka. validation. Often the networks of the individuals outside of the relationship need strengthening.
When the situation is more stable again I think there is a need to reconnect and regroup as a couple. That requires more disclosure, deeper validation, some vulnerability and new boundaries between the two. I'm talking here less about core personality protecting boundaries but more boundaries that to an extent are negotiable. Ideally (note: non speaking here ) one would negotiate and done but we all know we are not in a totally rationale relationship. So some conflict and fighting required in finding a new long term viable setup. Nothing wrong with conflict here e.g. one model of generic team formation enumerates the phases: forming, storming, norming and performing.
Will MC help or hinder progress only you can decide.
Am I holding back out of fear or instinct?
Fear of conflict?
Instinct that MC triggers too much conflict to be managed by your H?
Fear of change?
or?