CC, I think, from reading your posts, that what you really seem to want, is your H but with the excitement that the OM provides. Do you actually want the OM himself, or just what he gives you (physically and/or emotionally)? You say yourself that you would still have chosen H over OM 10 years ago...Could you explain this to your H and see if there's a way to work that spark back into your marriage instead of you needing to go elsewhere? (And I don't mean give him a BJ, that's not the answer!) You may have to be brutally honest with him, which will hurt him and upset you both, but at the moment you're not really going anywhere and, judgements about morals and right and wrongs aside, it sounds like all 3 of you are in some kind of painful limbo. And don't underestimate your children: they pick up on a lot, I'm sure they will know something is going on, which won't be doing them a lot of good either.
I'm not condoning what you've done, but I'm not against you either: shit happens, we all make the wrong decisions about something at one time or another and you've done what you've done, and that can't be undone. Some of us are stronger emotionally than others, and we would all react differently to given situations, so I think the harsh comments of others might have been a little uncalled for, as nobody else is in your exact same circumstances and nobody else is inside your head. What you need to do now is try to find a way out of this mess. That might mean you end up on your own with the children, it might mean you make a fresh start with your H. It might mean you end up running to the OM, which we can all see isn't a good idea, but it's easy for us to say that; we're not you, we're not there...
I do share mathanxiety's view though, that you might be moving closer to home, but unless the children lived there at some fairly recent point, recent enough to feel that where you live now is 'away', then yes, their home and roots are where you and they are now. But that said, I did have to move my children when my marriage ended and they adapted, but they were much younger (1 & 4). My parents also moved when I was 7 (as do many others, I'm not saying moving is wrong, just that they won't see it as going 'back', as you do, unless they already lived there), and it was odd, but I made friends. You need to be 100% honest with them and keep them in the loop at all times.