My 7 week old is poorly got a horrible chesty cough and cold. He was 4 weeks early and was in nicu…

My 7 week old is poorly got a horrible chesty cough and cold. He was 4 weeks early and was in nicu for 3 weeks. Took him doctors yesterday but told me to take him to children's ward at hospital. They said he's got viral infection they don't seem too concerned. But today he won't take any milk. Don't know what to do. His nappy is wet but he just wants to sleep