I would always say things like "I need to do things" or "I want to move forward". Being sick therefore would be really tough.
You are being sandbagged by your body.
But you only think like this when you are driven. Driven by some emotional program, some emotional strings and certainly not by your autonomous will.
Ideally, being sick is not a problem at all for you. It's the perfect sign for a healthy state of mind.
Enjoy the time off. Give your body some rest.