Yes, I think for now it is best to drop the 'we're a unit' thinking. Do you really want to be a unit with someone currently behaving in that way?
I wouldn't even tell him you need to look after yourself and detach - just do those things for you. There can always be hope, but I would drop the expectations. He could have had some sort of awakening, or you could be in for another round of the same again - only time will tell.
I'm sorry to hear about the breast lump and good luck for your appointment tomorrow xx
T 13 M 7 Me 48 H 46 SS 15 BD 7.14 PA D final 5.16 (H filed)
We receive & we lose, and must try to achieve gratitude & embrace with whole hearts whatever of life that remains after the losses - Dubus