Nobody has ever said your were stupid for still loving him. For most of us, and yes, this applies to those that HAVE the affairs as well as those left in their dust, love is not something that can be turned on and off. The thing you have to be careful of is that love makes you blind to things that could be ultimatly destructive to you and the kids. Taking him back now, without SOME kind of lasting actions to back up any words he may use to describe his feelings, would, yes, be stupid in my book.
I think you are perfectly normal to still love him and also to want the "old" him back. I also think it's great that you now recognize that the man he is today is NOT the man you married, or that you want in your life. Keep that perspective, keep working on you and please, keep those babies happy.