More reason to go through the courts. He needs to see an attorney and if the kid is his and he wants to be a father. They need to do custody changes in a public place and all communication needs to be written. It's perfectly fine for him to say "I'd like to handle this through the court system and I am not interested in having any relationship with you."

Get a DNA test and go through the courts to make custody arrangements. If the kid isn't yours, that's it. If the kid is yours decide how much contact you want. If the kid is yours, you will likely owe some child support.