hi.. he probably has a sore throat due to which he is afraid of the pain he feels when he swallows.. give him smooth items like soup or caramel custard

Both may be the reason. But main reason is cough n cold.  Whenever baby are not feeling well, they will reduce their intake. No need to worry. But keep baby hydrated. consult your doctor and give him cough syrup. once this is reduced...he will be eating normally. Can keep his head lil elevated. Add few drops of eucalyptus oil on the nearby pillow for easy breathing. ( can even keep some champhor on Luke warm water in the corner of ur room).