First, I'm very hopeful that you will fully recover, so hang in there.
Second, I always cut sitting down and it's not a problem. Just adjust your table, or chair so that you can reach and see your ruler clearly at the far end. Also, keep a sharp blade in your rotary cutter, so you don't have to push so hard. I have a feeling that once you start cutting while sitting down, you'll never cut standing up again. Good luck with your recovery!
~ Cindy