Hi Nana moon, I've just been reading about you going up and down stairs so often, and do agree with DogLover that if you could cut that down a bit things might improve for you. I am a week behind you, I had my right knee replaced on Jan 11th. Most days I stay upstairs all morning, resting, exercising, icing, elevating - literally I lay on the bed with my legs up the wall, it is so comfortable. I come down stairs for lunch and then may have a short trip out, or maybe a friend might pop in, and I don't go back up the stairs until bed time (luckily we do have a downstairs toilet). I can honestly say that my knee isn't swollen at all and I am not in any pain. I hope things improve for you very soon.
Take care x