I'm stuck on what to do?

So me and my baby's dad constantly are up and down up and down. He has two other kids, plus this one on the way( I only have one bby with him). He keeps saying how he'll change and get his life together and he's trying to change and wants to be a better father, I bought him an I phone when we were "together" & because ive been asking for help financially like diaper money wipes little things so that he will be good this is my second baby. I finally got fed up, and I blocked him. I'm done I want nothing more to do with him. I reached out to BOTH his parents and got no response he lives with mom and dad. I honestly could care less about him or his parents, because my baby has me and my family. I know things change once he's actually here but still, I'm just I'm done. The lies, manipulation, disrespect, he still hasn't told his parents, don't know if they've spoken to him about it dgaf either. I plan on getting child support. Would it be disrespectful for me to leave the child support papers and a birth announcement in his mailbox when baby comes? I'm sure he won't change, his other kids didn't change him, doubt this one will. I have NO INTENTIONS of contacting him telling him when I go in, nothing .