It is reassuring that you are actively managing your son's symptoms, but please do not add any new medications on your own. The treatments you have given Fepanil (paracetamol for fever and a cough reliever) can help, but a severe cough and fever in a toddler require a proper physical examination. It is very important that a paediatrician listens to the chest to check the lungs and safely guide any nebulization. Please consult your paediatrician today for an accurate diagnosis and to see if any treatment adjustments are needed. In the meantime, ensure he stays well-hydrated and comfortable.