Sorry to hear! Hope you are on the mend soon.
The good news is that there is tons to do in the area (depending on your interests) that is VERY close to your hotel.
There is shopping all along King’s Road, from pricey boutiques and cute indie shops to biggies like John Lewis in its iconic Peter Jones building home. There are TONS of places to eat (from Joe & the Juice to Polpo to Comptoire Libanese) and a few cool pubs, including the Chelsea Potter, which was a legendary rocker hangout in the 1960s. On Saturdays there is a lovely posh food market at Duke of York Square, with excellent food stalls and local produce. The Saatchi Gallery is only steps away. You could even walk to Chelsea Old Town Hall and watch wedding parties come out and stand on the steps for photos. :-)
Of course, if walking distance is the issue but you would be okay once you actually got someplace, you could grab an Uber or black cab to any destination you like. There are also plenty of bus routes in the area, with priority seats for folks with mobility issues. You’ll be close to Pimlico, Westminster, Chelsea, Belgravia, Knightsbridge… and of course South Kensington, which is packed with museums and easily accessible by bus and cab. So if you want to stay closer to the hotel, you’re smack in the middle of some of the most interesting, sight-seeable neighborhoods in London.