OP you have been flamed and whilst it is 'understandable' why some have been like they are, please do not assume that everyone feels that way about you.
My H cheated on me several times years before we split, I found out and we tried to work it out. It didnt work in the end, because we werent right for each other, which is why he cheated on me !!
I fully understand how it feels to be cheated on, its horrible, its undescriable pain, but its NOT THE END OF THE WORLD (although it perhaps feels like it at the time) and whatever anyone says about cheaters cheating on their children, THAT I dont agree with for a second. Your cheat on your partner, not on your children.
Nobody here knows what this mans marriage is like. It cant be that great otherwise he wouldnt have cheated.
I acted like a bloody angel when my H cheated on me, as though butter wouldnt melt and it was all his fault. Looking back things werent right and we should have dealt with it differently all round.
I understand cheating from both sides (not going into details with the other side) and its bloody painful from wherever you look at it! being the OW (or the OM) does not make you a bad person and affairs are NOT as sleazy as they are portrayed on here, although I do understand that can make the W feel better to think of it like that.
I do not think you are a bad person OP, I think that you are asking for help. This is a site for relationships and I would say that included the ones that are not 'conventional'
I hope that you come back OP, because I for one will support you.