If this is a boundary issue for you, then you handled it well.
How did you handle your conflicts before problems with M? Did you confront them or avoid them? Just asking to tell if whether your setting this boundary (and I think I would set the same one) is the same old, same old or a 180 - in your H's eyes.
I have to give you the same warning you guys have given me and I am sure will again. The weekend you had sounded great. And it was filled with progress. Just be very careful not to allow those wonderful strides to allow you to have expectations. Having those expectations will set you up fo disappointment (the down part of the roller coaster). They can also cause you to become impatient. You see good signs and you want more, NOW. (Of course, by "you" I mean us all).