9 month old twins sick for 3 weeks

last week i took my twins to their pediatric because they been sick for over 2 weeks and developed a horrible cough, we’re on week 3 and the cough seems to get worse and now every time they have a cough episode they throw up all the food they have eaten. i have tried everything they’re still super congested as well. i tried calling their pediatric multiple times and no one has picked up my last resort is just to take them to the children’s hospital at this point but if anyone has ever experienced something like this i would love some advice. ps. my toddler just started daycare and has us all sick