Sorry it took so LONG to find the problem but glad it will now be taken care of! Try to relax and think about the long term -- pain free days ahead! Will say a prayer for your successful surgery and smooth, speedy recovery!
My son just had surgery on his shoulder yesterday -- he is having his worst "day after" period right now. He came through very well though and the were able to make the repairs. I have him in a Donjoy Iceman contraption right now -- fancy electric icebag!
Icing your knee afterwards will help too!