severe stiffness and muscle pain

I had a RTKR on 1/2/08 and have been in outpatient PT since 1/14 @ 3x's a week. I can't pedal the stationery bike the entire way around without severe pain. They have me just rocking but I want to do more but I am afraid. There is no hands on manipulation just my exercises and I can't use ice because it makes my leg ache worse! Is the any advice for me? When I get up from sitting or laying down for even an hour-my leg gets so stiff and sore that it is hard to walk.