Congratulations! I realize it is going to be a very rough transition. It sounds as though you decided they have no business interrogating you. You cut them off more than they cut you.
I was terrified of not being active b/c of my extended family. They were long-term gung ho JWs. To my utter surprise, they constantly looked the other way, even when they discovered that I was doing more and more worldly things. Your parents may have a different slant when they are cut off from your son. Young children cannot discern different religious views from people they love.
There is a wonderful life on the other side. Hopefully, your family may find practice harder than thinking about something abstract.