Welcome back.
But yet they want me to drop off my son for them to spend time with as long as I dont speak to them when I do.
It must be hard as a single mum, and so you would need their help, but this is fraught with danger. They want your son without you there so as to indoctrinate him. It will create problems between you and your son, when he starts telling you that Jehovah doesn't love you and that you will die at Armageddon, or that you are not a good mother because you do not love Jehovah. Think twice before taking them up on their offer. They will not respect your request regarding not speaking about the religion, because they think his eternal life is at stake.
You are being abused and manipulated by your family, and need to stand up on your own if you are to retain any self respect and be able to prevent your child being put through the same cycle of abuse you have suffered all your life.