I don't breastfed my NICU baby

Hi, me and my baby are in NICU in Poland. He was transferred from one hospital to another and now he's in completely different city (which is the one I currently live in and my baby will too). He'll probably leave NICU soon, they say maybe in a week if everything's going to be fine.

When he was born at 28weeks he had some type of bacteria infection in the intestines, which prevent him from getting any milk - breastfed or formula. It was like that for 2 weeks. It literally devastated me. Doctors were saying it's not my fault that he can't get my milk etc. but I just felt horrible. All the milk I pumped went for nothing, only to freeze. After 2 weeks they started giving him like 2ml, later 5, 10... but my milk was gone, when he finally supposed to drink it. I tried every 3 hours, everyday, every night to pump, even longer when I supposed to. Nothing came out. Doctors are not helping with it either. So now my premature baby of 2 month that is still in NICU is getting formula and whenever new doctors or nurses are asking if I'm breastfeeding or not and I say no, I just feel such a guilt. Maybe I imagine this too, but I feel judged by them... Is any parent here don't breastfeed too?