I think that you are doing good by going to a MC with your H. Just like Jeff posted, leave no stone unturned.
My biggest concern...you are telling him that you do not like the swinging lifestyle, that you want to leave because of it and the way that he treats you and what does he do, argues his POV. HE also just put 'on a break' which really means that he thinks he can sway you to doing it again in the future. Then he gets satisfied twice on his terms. SELFISH, SELFISH, SELFISH!!!
He simple used you. I know that sounds harsh and I am sorry but that is exactly how I see it. If I tell my H no, sure he sulks a bit but I don't feel guilty about it, I'M just not interested and he should respect that. Your H obviously doesn't respect you when you say no. He knows that you will just do it.
Please be careful with this. I understand giving it a go with the MC, I did it too. But SET BOUNDERIES in the meantime. If he can't stay within the bounderies, you have your answer.
Me-31 Him-28 D1-9 D2-6 Married 5-06 Seperated 12-07 He filed 1-08 Reconciled 4-08 D dropped 7-08 Bomb dropped about H's activities outside the marriage 4-21-09 Filed for D 4-28-09 Trying to make a go of it 6-09