Baby is congested and very upset?

My son is also 4 month old and we went to the doctor a couple of weeks ago for it. the doctor put him on a medicine called c-phen drops it is a cough and decongestion you give them 1.4 every 6 hrs and it works great my son was better in 3 days also the nose suction will also help and also putting a humidifier in the babys room at night helps. Take her to the doc and bring up c-phen drops.