My dear friend, feel sorry for you and i pity your wife for being so cruel (to her own kid as she has no right to take decisions on behalf of the child just bcos she has given birth). I can imagine ur state of mind ....
I can see you going through many such insults/humiliations and frustrations as you go along the custody battle. It will drain you for sure as you seem to be a emotional person.
Remember , you either give up the custody of your child at this stage or fight in the court for next 5-7yrs with no guarantee that the custody will be given to you. And with each passing day your wife will keep instigating and spoiling the childs mind against you. Despite your efforts/Love/Sacrifices........One day the child when he will start understanding things will tell you on your face that he doesnt need you or doesnt want to see you !!!!!
I agree with Vakalath, pay your wife and get the custody of the child....
Im not against fighting for custody but you need to know its a very tough battle ahead. All the Best !!