Oh Nit I really feel for you and I know nothing will take away your pain right now.
It will believe me get easier and you will accept this (please do accept this) do not go on thinking like some that it won't last and he will be back de dah de dah.... You can waste so much of your life that way.IMO
I am not saying it will last but it could and do you want to put your life on hold for 5,10+ years just in case. My x rem and never told me or his kids! after telling us he had no intention of ever remarrying. A friend found out from local gossip and wrote to my SIL so he could tell my d and then all my childern came down one day to tell me. I think I always had one of them with me for about a week after that, such was their concern for me. We (my x and I) had grown up together and since early teens always been together so I was devastated becos I had believed him and thought the A would fizzle out after all thats what we are told 6mths -2yrs max. Affairs don't last, they never m them etc.
So much as it hurts right now this is your chance to put the past in the past and slowly find you and begin to live again. and you will.
Please don't take as long as me to do it though. ((((()))))))