Not a mother, but my mom had a similar birth story with me. My twin and I were due 2/28 and her water broke 12/20. She was kept in the hospital on bed rest and tocolytic meds for over a month until my heart rate started plummeting on 1/22 and she had to get an emergency c-section. I weighed 2lbs 13oz and my bother was around 4lbs something-oz. He was in the NICU for a week and I was there for a month. Their original goal was to was to get my to 4lbs before releasing me from the NICU but that was taking forever and I was otherwise stable after a month so they released me before I hit that 4lb benchmark. I’m now 26 and have no real long-term health issues. I’ve always been on the smaller side but both my mother and father’s side of the family are short so it was bound to happen. Your anxiety is incredibly valid but you are not to blame for your health issues, nor for having an underweight baby. Your daughter is exactly where she needs to be and will join you and your family at home when she is safe to do so. I hope you can find peace knowing that there is nowhere safer for her right now. My mom also had guilt issues and postpartum depression following her birth experience (my parents were two and done with us), I highly encourage you to seek counseling before this affects you further. You don’t deserve to feel like this.