Child care and child support

I’m a single mother of two. My kids father left me soon after we found out i was pregnant with our second. I’m almost done with my maternity leave and need to work a lot more then i used to. My mom used to watch my son but told me she can’t watch both kids everyday and she’ll only do one or two days. I’ve been scared to file for support bc my child’s father gets really threatening whenever I’ve mentioned it. So my question is; do you have to file for child support in order to get childcare?? I live in P.A. If that matters.