Physical pain

I have chronic knee pain in one of my knees. I had an injury and surgery 7 years ago, and I frequently still experience pain in that knee. I am an athlete and I have a very strong reaction when I feel the pain. “I don’t want this” is a thought I commonly experience. I feel a lot of discouragement, and even despair, on days when my knee is flared up. I have done a lot of thought work on this, trying to change my thoughts about the knee pain. But, I still have a lot of resistance and I know that is making things worse for me. How can I move past my discouragement that this is my reality? How do I get to a place of acceptance?