I have Interstitial lung disease. Coughing and S,O.B upon exertion.

I have oxygen if I need it. I have to use the portable tank when walking on treadmill. My pulmonologist has me on Ofed. I have an inhaler I use twice a day, and a nebulizer if needed. I also have asthma.
I have had three CT scans and two chest xrays. My fibrosis is in both lungs. My recent xray shows " increased marking in both lungs extending to the upper lungs to the bases and appear to involve both peripheral and central lung"
I live in Springfield Illinois. My pulmonologist has made an appointment for meat the pulmonary specialty part of Washington University in St. Louis Missouri. He said they will probably want to perform a lung biopsy.
Has anyone else experienced this.
I am frightened. I feel more frightened when the coughing starts.