Anxiety disorder...as bad as PTSD?

Hi, I'm an 18 year old female. Within the past year and a half, I have had two reconstructive knee surgeries for each knee. For both, I had to repair a torn ACL and meniscus in both knees. I got injured in volleyball. Anyway, I no longer trust my body. I am PETRIFIED to do anything that requires impact with my knees. Things like running, jumping, or pivoting. The thought of doing any of them makes me want to cry. I often find myself watching a sport game on TV and see an athlete doing something that could possibly result in injury, and then I'll shutter, close my eyes tight, hug my knees, and turn the TV off. It's like painful for me. My dad is forcing me to go back to the gym next week for the first time since my surgeries. I sat in bed all day crying. I feel like such a loser. I can't stand it. I feel like I'm going psycho. Can this be considered PTSD or another anxiety disorder? Thanks for any suggestions.