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Use the problems of your left knee as a reason to develop a lefty forehand. On a lefty forehand you plant on the right knee, which spares your bad knee from stress.
Since most courses are righty friendly, a lefty forehand flies the same way as a righty backhand and will give you a huge advantage in dealing with righty hyzer tunnels you will encounter a billion times in the future. By next spring you may have a solid forehand and your left knee may have recovered enough to let you drive comfortably LHBH.
This occurs to me because my bad right knee forced me to learn a forehand, which is now my primary drive. I sure wish I was lefthanded, like you.