aha -
I know that you are crushed to say the least about these events.
Please read all you can on this website and unfortunately you will find that your situation is very similiar to many many many people, but fortunately, you have found a place to receive help and advice.
Please also get a support system in place for yourself right now - a counselor, friends, family, a chirch group, prayer, or all of the above, this is a very emotionally trying time and you will need some help to get through it.
It's almost too early to tell what is actually going on inside your wife's head - and truthfullly, she may not even know herself. She may just know that she's unhappy and not know exactly why, or she could be having an emotional or physical affair. It's more likely than not that when people leave that suddenly that there is someone else who they are leaving for.
If this is the case, gather as much info. as you can to see if this is true because you may need evidence for court later (I know that you don't want to think about that now, but I had to mention it). You may also want to read Surviving an Affair of which Plan A and Plan B work well for midl ife crises too.
You want to look at the marriage, identify her needs and meet them. And you need to find out what destroys her love for you - and stop doing those actions. There are questionaires to assist you on this site that you can print out and fill out as if you were your wife.
Beggin and pleading with her will most probably will not help and of course she will say that her son will be ok - she will rationalize anything to defend her position.
I would take things slowly right now, don't make any rash or hasty decisions. Take care of your son and give your wife some time while you figure out what you want to do.
I hope some of this helps you. I will send some prayers your way.
K
