I was off work for 3 weeks after both my scopes, office job. No driving for 3 weeks after the first one, 2nd one I could drive once comfortable - automatic, left knee, so about a week, will be different for the right knee, you need to be comfortable making an emergency stop
I used the crutches on and off for 3 weeks after the first op (meniscus trim, debridement of kneecap), 2nd op, didn;t need them (wash out, tidy up)
Can you afford to have some private physio? Are you icing several times a day and doing exercises (heel slides, ankle pumps, leg raises)? Ice, always wrap the ice pack in a tea towel and never more than 15 minutes at a time
3 weeks after any surgery is very small - don't be fooled by the small holes, your knee has had a trauma during that operation
If you are worried, see the surgeon or at the very least, your GP.