Can thrush cause your baby to be super fussy? My son has thrush and his doctor prescribed him some antibiotics that I give to him every 8 hours. I've been doing it for about a week. The last 3 days he's been screaming at the top of his lungs if he's awake and not eating. I thought maybe he was still hungry and I already feed him 3oz and he's only 3 weeks old. I gave him 3.5oz at 1am and he was screaming again so it's not that. He won't take his pacifier. He will still scream if I try swaddling him, cuddling him close, going outside, walking around with him, rocking him, changing him, everything. Idk what to do?