Son’s colds last FOREVER

My son (now 18M) gets sick every couple months since starting daycare at 11M.

His doctor will sometimes give him antibiotics if they feel it has progressed to a sinus infection or if his ears look bad, other times no. I do THE WORKS for him, I give him a steamy bathroom to bathe in, keep his feet covered, vitamins + Pediasure (bc he’s a terrible eater), Motrin if he has a fever and Zarbees for mucus, Vick’s plug-ins... the list continues.

Nonetheless he will get to this phase where he’s not fully sick and lethargic anymore, but he still has this mucus and cough that just LINGERS!

Week 1 will be bad and you can tell he’s truly sick for 2-3 days, lethargic, very ill seeming. Then his temperament will improve and he will be happy, the fever will be gone, but he still won’t be interested in food and he will have this runny nose and cough for like 2 or 3more weeks! It happens every time... meanwhile the other kids at daycare who got sick with the same thing are just peachy.

He has allergies so I know that can make things worse, but it’s just so frustrating and sad to see him unable to shake the mucus! Meanwhile I’m afraid to do anything with him for entire months at a time while he’s still sort of sick, and I feel like we’re both missing out on fun things outside of the home together.

Does this happen to anybody else? Any advice?