Lostkitty...keep in mind that just messages is still an A. It is no different than saying it was just an emotional affair. He still stepped away from his relationship with you.
I understand the feeling of not wanting to walk away from your current life. I too said that in the beginning, as I have been married 25 yrs. I am lucky we are looking towards R.
Take time for you right now and take care of yourself and your son. Don't make any hard decisions yet, there is no pressure or time line. My advice would be to keep reading, if you are afraid of conflict you may be just like myself...a co dependant spouse. If you feel that is so, then the book "Codependant No More" is a great read.
If you can afford IC do so, consider doing the 180 for your own strength so that you can create an environment where you can make decisions. The other thing to consider is seeing a lawyer...just to get advice on what you are entitled to should the relationship break up. You deserve to have information to protect yourself and your son.
Good luck, may you find your path.