The wedding ring is huge, that is fantastic. Now is the time to re-read DB and start looking at what you can do.
I'd like to offer a different opinion of an ultamatium -- 1) what good would it do? He knows that for you to believe he is serious about the M and willing to work with him to repair the M, the contact must be ceased. That is known. 2) Right or Wrong, he might need time to "grieve" the end of the relationship. If it is his choice to end this, not something you forced him, I think that is going to make for a much stronger base to move forward.
Take the thoughts for what they are worth, but after living throught a bunch of this, it is what I've learned.
