Too much exercise may actually not be ok at this point since your body is really still sick.
“Too much” exercise can be harmful regardless of your fitness level. If you’re recovering from a serious illness or injury, naturally you should check with a medical professional regarding exercise.
My personal experience has been that a reasonable amount of exercise, along with proper diet and adequate rest, is the best way of preventing and alleviating the bulk of physical aliments. And the older you are, the more benefit you get from exercise.
Prayer and Torah study helps too 🙂