Hunger pains and reflux at 6-7 weeks pp?

Has anyone else experienced bad hunger pains pp? I started having horrible hunger pains and some reflux in the morning. Once I eat they go away but start to come back a few hours later. I have never experienced this, even while pregnant. I was breastfeeding but my son was not gaining enough weight, so my doctor recommended we supplement with formula. Since doing so my supply dipped even more so now I just pump a 2-3 days so I don’t think the hunger pains are related to that?

I called my doctor and she prescribed anti-acid medication that isn’t working. Wondering if anyone else is experiencing pain this postpartum?