Since you have a son, my advice would be to crash in the apartment that is one mile away and let her stay in the house with your boy.
I am in a VERY similar situation, we separated on 9/29 and my wife lives in a VERY nice home with my daughter while I crash in my friend's fraternity house.
I have just started to embrace by new life, it's REALLY difficult.
If you want to stay married, I strongly suggest Michele's book and the last resort technique. It's most likely your only chance for saving the marriage.
