Sorry you are having a difficult time with your family. From an outsider perspective, it seems like no one in your family has healthy boundaries at all. I cannot imagine my family commenting on my parenting in anything but a positive way, or if they had a concern, they would approach it in an inquiring and supportive way, not critically. As far as you father goes, you may just need to set a boundary with him. Your son is an adult. If your father has anything to say TO your son, he should do so directly and not criticize your son through you. If his complaint is with your parenting, again, remind him your son is an adult now, so his decisions and life are in his own control.

I was pleased to read that you recognize your parents did things wrong and they bear responsibility for that; I hope you can go a bit further and take that responsibility off yourself. You were a child. Difficult or not, it was the adults' responsibility to figure out how to work with a difficult child so as to be supportive and help you find peace and healing; that's what good parents do. They may not get it right all the time, but good parents own that responsibility as their own and just feel horribly that their child is suffering. They realize the child, as difficult as he/she may be, is acting out in response to stress and not intentionally setting out to create problems.