Confused¿?

I had my son 4 days ago. My life changed forever, Thr joy of holding my bundle in my arms was everything. So his dad and I split at 4 months pregnant (Because he cheated). So he comes to see our son he sits takes pictures and post all over facebook like a great father. Friday he decides to call at 845 thinking he could bring his other children to meet their new little brother, not a problem until he wants to bring their mom as well. I don't know her and they are not together so no need. Right? He blows up and throws a fit. He even disrespects my mom as she answers my phone because I had just had a c section 18 hours before(Even while there he was rude to my mom). So he didn't come back to the hospital at all and I haven't heard from him since Friday night. He text tonight asking is it to late to sign the birth certificate. Ugh. When I see his name pop up I get scared sad and cry automatically idk why but i would rather he stay away. What do I do?!.