Sorry to hear this. Unfortunately, people do get sick. I can appreciate how frustrating this is, but I agree with Tudor Queen, you can use this time well, and could see it as a gift, because imagine all the pressure and stress you've been through, you can now release some of that by relaxation, exercise, and have additional time to go over your thesis. If you want, you could even look for typos and send a list to examiners before-hand or have it with you in the viva, that looks good to them.