Cat scan from 4 yrs ago showed fibrosis of lungs. recent scan has some progression but also have shortness of breath now. will this progress faster?

Probably seems so.: Lung volumes in idiopathic pulmonary fibrosis generally decline at a rate of about 200ml/yr. Once you are symptomatic anny further decline is felt as "progression" whereas the first few years of disease were spent at a level above your ability to detect any decline. Therefore, the disease seems to pick up speed, but it is just an illusion.