There's no set time when swelling comes and goes. Just do the best you can with icing and elevating and is should gradually go down. Ice until it gets uncomfortable, then give your knee rest and ice again. You could try putting some extra material between your knee and the icing medium, so that it isn't quite so cold. See if that helps.
Make sure that you keep o your schedule for taking the medications.
We do say that no two knees are the same, and your second one is proving that. It could be that this knee needed more work during surgery than your first knee. That doesn't mean it won't do just as well eventually, but it might need a little longer.