Any riding is good riding. If you want to keep your options open get an inexpensive Honda Rebel or some other old 250 in good running condition, or even a scooter. Sell you RE and Yamaha and get the money out of them. Less money tied up, less garage space taken up. If your health improves and you have a good day, take a short ride. If it's a bad day, choose not to ride. Don't endanger yourself or others but making it your choice can make all the difference. I know what it feels like when your health can limit your choices about your life. Take it a day at a time.
Scott