Worried mama with LO not eating and drinking

I don't know what else to do. Hopefully by being here could get some tios and advices from mummies out there. My son today his 1st birthday! Since 30th aug, he caught stomach flu from school, he doesn't want to eat his puree, porridge, cereal. Drink formula milk also abit. Never once finish. His weight 7.9 last check on last monday. Today his favourite teether snack also he don't want to eat. I everyday get scolded from husband cause my son not eating when I try to feed him he doesn't want to eat. #advicepls