I have had a similar experience with beta blockers after only one year. Lethargic, major loss of fitness (was a competitive cyclist), major weight gain. The doctor tells me that everyone my age takes this, and that I should have more realistic expectations. I fired that doctor. It’s been a long road getting back in shape.
This doctor teaches at University of Texas Medical School.
Yep, exercising was near impossible for me. Now I cycle and walk regularly with no problem.