Just be available for the visits but don't really expect him. Keep avoiding the tendency to respond to the texts - he really doesn't expect a response. I can imagine how hard it is to have a child that you together but what I said before - each child has his/her own relationship with each parent - if you try to get inbetween them all the anger falls on you and YOU DO NOT DESERVE IT.
I am glad to be here, you have been helpful to me and allowed me the room to grow in strength, as I hope you will be also.