What Could Severe Cold With Nose Congestion In Infants Suggest?

Hello Doctor,my 4 month old baby has cold and cough.he is suferring from severe nose congestion.he is sneezing,wheezing,coughing.i'm using little noses saline drops for cold.Other than Saline drops,Could you please suggest me any medicine for cold and cough.I was just wondering if it was neccessary to take him to the doctor?? Thanks in adance