You did alright. Ok you’re going to make mistakes the important thing is you recognize them and don't repeat them. You are not even close to being detached yet, forgive yourself for that it's normal. One of my biggest mistakes was always beating myself up after I slipped but you can recover from that. Every time I read one of the bits post I see so much progress from the beginning of their ordeal to the present.
Don't bring up the R/M talk at all. I can't stress enough to be happy with you (easier said than done) but you must try. When you know you are going to see him take a few minutes to calm yourself and remember that you are in a chess game. Don't give the opponent all the moves and don't show your hand. After he leaves burry your face in a pillow and scream but in front of him you remain composed.
Give yourself the time to cry and detach. Maybe going dark for a few days or even a week would help. He is hurting also I promise you that. You don't spend 18yrs with somebody and all of a sudden hit a delete button. You can only control YOU, remember that and the rest will fall into place.