New mom please help

New mom, confused help please

My son was born 3 days ago, he was taken to the NICU, I am not breastfeeding atm, we are using formula. Since then he is so much more fussier than day 1 and 2 with him.

He won’t sleep longer than 30 minutes. The first day he slept practically all day, second day he did the same thing, then he went to NICU and came back and now won’t sleep at all.

He is fed, he is changed, he is cuddled.

I’m not expecting him to be amazing at sleep I’m not stupid, I just don’t know how else to encourage him to sleep longer.

He’s already lost two pounds, so we tried to up his formula intake, but he won’t finish the bottles. He also hasn’t pooped in two days, but the doctors keep saying they aren’t concerned.

Does anyone have any ideas?