Thanks for an update. Already 5 months without sense of smell, that's unbelievable.
Coming back to training after a many days in bed can be super intense and in my opinion should be done very slowly.
I would start with the light yoga exercises
https://betterme.world/articles/chair-yoga-guide/ and then make it more and more active day after day.
Cycling is definitely not an options for the first couple of days after the illness.