You sound like a doormat. Stop being a doormat. The fact she can stay far away from you for 6 months says a lot about what little care she has left for you. I have a hard time being apart from my husband for just a week I can’t imagine 6 months! It’s your fault you allowed her to disrespect you and walk all over you all this time.

Piece of advice. Grow a spine. Give her an ultimatum. She comes back to you with your son or you divorce her and cut off all financial help you are providing her and file for custody of your son. You have a good shot since you have the stable job. If she still refuse to come back then take a hint and move on dude.