Congratulations on your new knee!
Is the cold therapy machine the kind that circulates ice water around the knee? I borrowed one from a friend for my post-op period and that plus my frozen 'peas' were a godsend.
Really for the first 10 weeks I did a LOT of 'laying around' icing and elevating.
You are still so early in the recovery period, so don't fret yet about swelling and rom. Some days there is great progress and other days you feel like you are regressing. Just be patient. It won't all be healed at 8 weeks or 12 weeks or even 30 weeks, it takes a very long time. My OS said the knee could continue to swell for a year post-op.
I am coming up to a year now and even with a glitch that I experienced I still am so glad I had it done, and I feel terrific. You will too!