Good morning Foxy - (whoops almost good afternoon) - had a Sunday lay in!
If your knee is red and swollen, remember its still really early days. Don't beat yourself up about needing to rest it at this stage - as you need to let healing commence. My knee is still badly swollen even now, but I am persevering and it is slowly but surely responding.
As you are finding, the more you do, the more it swells - sitting in the car is painful too ( I spend most of the 30 min journey to each physio session furiously fiddling with the seat controls) and ........ it swells! Everything seems to make the blessed thing swell.
As everyone here keeps saying, the only way is to: elevate and ice, elevate and ice.
As for the stiffening, best advice I have had is, just a little movement (not necessarily exercises) frequently, to stop the log leg stiffening too much. Just try not to get yourself stuck in one spot for too long.
Hope you have a brill day - its great to be back home isn't it??
BTW - what sort of terriers are your dogs???
ChrisX