Have you read "Divorce Remedy"? If not, go get a copy and pay extra attention to parts about the last resort technique and affairs. Then read the whole thing again. Also check the last resort posts on this board.
Right now you need to do some dammage control for you, your marriage, and especially for your son.
Stop asking about the affair or snooping. You already know it is happening and he is not going to admit to it right now. You are only retraumatizing yourself and helping your husband build a case against you and your marriage in his own mind.
If you can stay in the house, but you will have to make the call. Spend time away from home when he is there as much as you need, but moving out is hard to come back from.
Try to take care of your immediate physical needs. Eat something healthy and comforting. Take some B vitamins. Get some sleep. I went for days without sleeping and got a nasty sinus infection as a result. I got some sleeping pills from my doctor, and it got me through the worst of it.
Ask friends and family for help caring for your son. I know first hand how hard it is to care for a little one when you are dealing with the immediate fallout from such a difficult situation. I know how hard it is, but he needs you to pull yourself together.
Be strong, even if you don't feel like it. This is going to be tough, and it is going to take time.
