Need help!!

So my 7 year old's dad is taking me to court to try and get full custody of our son. You see since we split up when our son was 3 I took primary care of him and his dad only wanted some weekends. Now in the court forms I received he stats I keep him away and that now he wants full custody and for me to have some visitation rights.

He made me sound horrible in the papers I read but it's all things I have done to him. I'm a great mom. I just don't understand why now.