I am a training development manager, I sit in the office, stand in front of classes and assess trainers in their workplace which could be a field, class, office basically anywhere. I drive 100/150 miles a day.
This all sounds good and you should be fine.

My current exercise regime is limited because of the swelling and pain but I manage 10mins bike, leg raises, sliding knee bend, small squats, calf streches and walking for about 30mins. This is spread over the day with icing between. I have 30mins physio massage one a week.
sounds like you are doing lots exercise-wise. One comment though - as you are 3 1/2 months down the track one usually find the pain and swelling has settled a lot. So when you talk to the surgeon do ask him why he thinks you are having so much problem.