I need a knee replacement. do you think ii should have both knees done at same time. one hurts worst then the other but i am worried .

It's possible: You have to have the talk with your surgeon. Most if the time they recommend one at a time. When you have both done at the same time the recovery is more difficult but then it's over. If you are in very good physical shape, healthy, low surgical risk and are absolutely sure you want to do both then go for it. My mother did at your age so she wouldn't miss a summer of golf!