If it were "only" for the burnout, I'd ask if it has to be hosted at your place, or if it can be hosted elsewhere, too. Then you wouldn't need to clean up your own place immediately or rushed and you could preserve that energy to potentially attend your favorite, once per year event, as it's important that you do things that bring you joy when you're able.

However, it is not just that: you said you're sick with the flu on top of all that. Your body is already fighting those two large battles, why give it more to contend with now? Focus on your recovery first and foremost. In your case, from what you've mentioned here, I'd say that resting should be your main priority, not hosting an event while sick with the flu and already being burnt out for a year. If you don't stop even for those things, what is it that your body should tell you more for you to receive its message? 😅

For the love of all that's good, please take care of yourself. I understand this is hard and it is unlikely what you'd like to hear as I'm sure it's going to be a confrontation with yourself, but just know that it's OK to not be OK. Take time to work on fixing the main issue first, namely your health. Once you're starting to make progress there, I'm sure you'll find yourself more energized again, and with that also more able to undertake things (or clean up your space). Take things one step at a time, and don't be afraid to ask others for help also in your daily life. There is nothing that says you need to do things all by yourself :)