Help Please Child Bronchitis

Hi! My son is 4 1/2 years old. He has been healthy in the past. This year he is been 6 sick times with bronchitis. I know he has been expose to sick people.
He started on Monday with pulsatilla. It seems to help, he doesn't cough as much, but when he does his cough is still wet, gets worse in the morning and night, he seems to be better outside, he is thirsty for cold drinks or ice, wich i cannot give it to him while he is sick. He first start with runny nose for a few days, then 2 days with a dry cough and then the bronchial cough. I been giving him Pulsatilla 30 C since Monday 3 times a day with combination with Sambucus, but the cough still there. It seems that the cough is some how controlled but I don't see any improvement with the cough, the did spit one day and it was white plegm. he doesn't have ear infections I took with a regular doctor to check him. I Did the nebulizer two days at the beginning. but know tomorrow it will be the 8th day. How long can a cough last? It will affect my child lungs?
He likes to be held a lot, he likes company and wants attention, wants to be loved, he doesn't like to be alone at night time, he is eating well, he sweats at night time.