I know you will be glad you had the surgery once you get your ROM back. That takes a lot of PT. My daughter just had a partial replacement of her right knee. It's been tough for her to bend the knee but she is still going to PT. She can't drive to work until she can bend the knee enough to manage the pedals.
I had both total knee replacements in 1997, same time. I was so glad I had it done and over with and once I was healed, I felt so much better. Keep up the rehab and soon you will be walking without pain!