Newborn screams

I had my son 1/21 and since I’ve brought him home he screams during diaper changes . He’s on formula since I can’t breastfeed due to the medication I’m on but he poops yellow after every single feeding . I also got him circumcised . It’s Saturday so the children’s clinic is closed til Monday and I feel so bad . Anyone else experienced anything like this with their newborns ?

* also his cord stump fell off early, is there anything I should put on it ? I noticed it fell off from blood on his onesies 😪