What Causes Breathlessness, Leg Swelling And Fatigue While Climbing Stairs?

I have shortness of breath when walking especially up stairs. I ache all over, fatigue, left leg and ankle swells very badly. After it gets very bad, then the right swells. When I walk the dog, after a few blocks I hurt terribly around my shoulders and upper back. It hurts up my back a bit around my neck. I have had hypersensitivity pneumonitis, was on oxygen for 5 yrs, got off by walking to build up my strength. Now I have been diagnosed with pulmonary fibrosis in the bottom lobe of both lungs. Would like a truthful answer on what is happening to me. Getting evasive answers but not how long or things like that. Would like reference to materials to read or idea of what to expect.