How do I find out

I have been told an adoption can be contested for up to 6 months after an adoption. I was pushed into letting my mother adopt my son and I do not feel he is in a good place with her. Her husband was in a wreck last year and is now permenatly brain damaged because he drove drunk. I was in an abusive relationship and had no way out so instead of helping me she took me to court but they only took my 7 year old away and left my infant. Now my son is in a home with someone who's moods are unpredictible and can be a danger to himself and to others, How can I get help to see if I can fight this. I am out of my relationship and getting back on my feet, and my son who is now 9 who i have kept in contact with and see on a daily basis is now being told to call his grandma mom. She is messing with his head terribly and I need to help him fast. I should have never let this happen to him in the first place but i was a scared abused kid. My mother was also abusive to me as a child and i am afraid since my son acts like me she'll do it to him too.. I would appreciate any and all help. And dont I have to be notified of the final hearing?