I'm concerned about your being in MC.
Mc treats the M, and the M didn't fail - your H failed. He needs IC to get get help changing from cheater to good partner, IMO.
MC right after d-day can be good is the MC addresses the A first and puts off addressing M issues until the A is addressed. For us (W got us time with her IC on d-day, and her IC was a great MC, too), for months our sessions were all about my perceptions of the A vs my W's, and MC worked to get my W to see how W's dysfunction fucked up our lives.
During our sessions, my W said she was honestly afraid of me when I used a specific tone of voice, so MC worked with me to 'hear' that TOV and change it. That took a while, but it solved the problem. Other than that, it was all A, all the time for months. And if an A-related trigger occurred, we went ack to all A, all the time until the trigger was taken care of.
But our MC was crystal clear - to R, my W had to change, and that change was going to come much more from IC than from MC.
Your H caused the A. He is the biggest problem in your M. He almost definitely needs IC to get help changing from cheater to good partner.
fBH (me) - on d-day: 66, Married 43, together 45, same sex ap
DDay - 12/22/2010
Recover'd and R'ed
You don't have to like your boundaries. You just have to set and enforce them.