Bless your heart. Yes it does hurt. But you know, sometimes staying together is WORSE for the children than divorcing.

The fights and arguments really take a terrible toll on kids, that lasts well into adulthood. By divorcing, at least each home is happier than it was by staying together.
When Dad has the son, he can spend more time with him than he did while you were together! Plus the boy doesn't have to worry about any fights while he's with him.
And the same when he's with you at home. As long as he feels secure, and you've explained things to him so he understands that he had NOTHING to do with your decision, he'll be just fine. There are some kids that have difficulty with their parents divorcing, so be mindful of that and if you see signs of that in your son, make SURE you get him counseling at the FIRST sign of anything!!! Don't wait until things get out of hand.

My granddaughter came to me when I had her for a couple of years (she was 15) and her parents had split. She ASKED me for counseling -- she was seriously depressed, and she had been HIDING that she had started cutting herself!!!!

So I immediately got her into counseling, and she's still seeing a counselor.
I wish you the very best. God bless and take care. Hugs, Lee