I have a problem with my lungs, diagnosed with bacterial pneumonia?

Hello i am a 26 year old male.My problem started in late May 2016 when i came down with a fever, cough and overall sickness.i went to the hospital and they said i likely have a virus.They sent me home to take tylenol together with ibuprofen for the symptoms.I felt alot better shortly after.Over the next two weeks in late May and early June i started coughing a’lot with a a’lot of thick brown mucus.The mucus became blood tinged and i went to the hospital where i was diagnosed with bacterial pneumonia.I was given two different antibiotics which i completed.Follow up xray after antibiotics showed clear lung and clear breathing.Second follow up xray a month later showed the same thing, clear lungs.Ever since the pneumonia i have had frequent excess mucus and sore throats.I Recently had alot of sputum and felt sick again and was given a zpack.Felt better after z pack but now October 2016 i have another sore throat with mucus.Ever since the pneumonia i haven’t been healthy.What could it be, i feel like pneumonia keeps trying to form.There is no cystic fibrosis in my family and only 1 person my moms mother had chronic bronchitis.I have never had any issues with my lungs or getting sick.My TB test was negative and 2 HIV tests were negative.Hepatitis was negative also.Two blood tests in this span were completely normal.Please help.