Good evening Viviane,
Regarding the negotiation with your tenant, if you neither accepted nor declined the offer, it's possible that Airbnb considered this a lack of responsiveness, which could have impacted your response rating.
Please note that you are at home, and you can do what you want. If you don't feel like hosting, don't force yourself; we're not hotels, but private individuals.
In this type of situation, it's generally better to decline the request if you need more time to think. You can then propose a new personalized offer once you've done your calculations.
If you think this rating is unjustified, you can contact Airbnb support to ask for clarification and see if it can be resolved.
Please let me know if you need further assistance.
Sincerely,
Catherine