Managing multiple conditions - suffer from serious fatigue

I am a 72 year old woman, diagnosed with PH with LVDD. I am currently taking no medication for the heart/lung disease. There apparently are none while those in group 1 now have about 16 meds for their condition. Frustrating! I am told to exercise, lose weight. Problem is I have osteo in my spine and knees and exercise is very difficult. I suffer from serious fatigue because of other meds I take; just added Femara after breast cancer surgery in Jan. and Feb. Another load of fatigue. Anyone out there have this and how do you deal with it. I was told when diagnosed the average lifespan after diagnosis is 5 years. I am approaching that anniversary. So far my PFT's haven't changed in three years. Echoes don't show much muscularization on the left ventricle but can only see the backside, not inside it. I feel lousy a lot of the time and really want to feel better. I was diagnosed using a Right Heart Cath after a stress test with and without contrast, PFT'S, and echoes.