7 week old son is congested any tips?

my son is 7 weeks old and he has been stuffy for about 2 weeks now.. it was like hard mucous.. weve been putting saline drops and using the nasal aspirator to clear out his nose.. since he couldnt breath too well.. but since last night he sounds congested and we cant see any mucous in his nose and as much as we put saline drops and use the nasal aspirator nothing.. and he'll breath in and gag.. and then starts screaming.. im not sure of what to do to clear his throat or nose.. any tips? we were just recommended the saline drops by his doctor when his nose was stuffed .. ill be calling her tomorrow but just wanted to know what worked for your children.. thank u very much in advance