Aspiration. Or it will be too late!

2 months old bottle fed from birth. Got pneumonia when 15days old on antibiotics for 8days. We have consulted 5 pediatrician but they said everything is OK. They just check by stethoscope. But infant is breathing fast during and after feeds. Make strange sounds and excess salivation he Coughs when lying .nobody believes me now. Can stethoscope tell every thing from lungs.lot of hairfall like bunch of hairfall I think he is aspirating will he recover with no breast feed And so much antibiotic treatment. Whom should i consult. A pediatrician or pulmonologist. I m afraid effect of antibiotic on liver and kidney also.everybody says dnt worry till he take feed.. Whether less feeds but all OK.should I wait till he stop feeding or it will be too late