Should I have to ask?

Me and sons father are not together. He doesn’t help with finances at all. I asked for money to buy things for baby a month before he was born and he said no. Now I filed for child support and he’s saying I never ask for help. I said well I’m not going to keep asking you already said no once. Should I have to ask my sons father for help ? Isn’t it obvious that he needs things clothes diapers wipes formula blankets etc? i also asked for him to buy the baby things if he doesn’t want to give me money and he says ok but then I ask did you get him the stuff and he’ll just ignore me and ghost me .Now he’s calling me a disgrace and poor excuse of a mother because I put him on child support when the baby is only a month old.