Blaming myself for preterm baby

I had my baby 3 days ago at exactly 29 weeks. I had my doctors appointment 4 days before and everything was good. All of a sudden, I had high blood pressure, protein in urine and the emergency room told me I’d have to give birth because he was too small for his gestational age. I have been miserable since then and cry all the time. It feels like it’s my fault for not noticing new symptoms. I feel so sad every time I see my baby in the incubator because it feels like my fault. The midwives suggest I pump every 3 hours or so and I cry every time because my milk is so small. Something else I’m bad at