Hello @Megh0,
Please take care of yourself.
I don't think airbnb will offer any concession here. You can try 2 things:
1) Convince the guest that you are unwell and won't be able to host and request them to cancel the booking.
2) If the guest refuses, atleast they'll know when they arrive that you've hurt yourself so they won't expect too much. If you have any friends who could help you with the cleaning, request them for a favour if it's worth.
If both options fails, please cancel the booking yourself, bear the penalty and take care of yourself, remember health is wealth 🙂
Wish you a speedy recovery
Jeet