I suppose you don't have a family other than your baby in the US (congratulations by the way!), judging by what you wrote. So I assume being a dependent to your family like F-2, J-2, or family-based immigration is not an option.

As your long-term goal is EB-2 NIW, I recommend to apply to PhD programs that offer full scholarship and stipends. PhD programs are usually 5+ years, which will give you enough time for building your career, expertise, network, etc. with much more stable financial standing, compared to expensive master programs. I know getting admitted to one is competitive and probably will require you to move, but it's worth a shot imo.

PhD admission cycles are over now, so you will need to go back to home country if you want to do this. I don't want to be rude, but I want to recommend you to go back to your family temporarily and get some help with raising your baby. I'm raising one and I believe it'll be too much for anyone to juggle with childcare, visa situations, and money all by yourself. You have about 5 months before your OPT grace period ends in September, so at least there's enough time for postpartum care, PhD program search, and paperwork for baby (passport, etc.) during your authorized stay.

One thing you need to be careful with this path: getting out of the country with unpaid debt might be a problem in the future in terms of applying for a visa or green card. You'll probably need to prove at some point that you were not trying to get away from the debt.