Knee Pain- Part 2

Had a cortisone shot on Wednesday morning- then did 4 hours on the trainer Wednesday PM, and 6 1/2 on Friday (today) Was looking to go longer but knee pain persisted when putting a heavy load on the knee (out of the saddle for example) Hopefully the cortisone "kicks in" fully soon- as I need to get outside miles in- which have been the ones that hurt my knee the most. Hope to ride 50 on Sunday (will take Saturday off) to give me 300 miles for the week. I need to get an outdoor century in comfortably (meaning no knee pain) by end of April or I am not sure RAW will be doable. The thighs and muscles are fine- it is just the knee pain that is tough to endure..