The message is sitting there and you already know the answer is no, and you are typing out the third draft of a paragraph explaining why.

Delete the paragraph. No is a full sentence. It does not need a reason attached, and it does not need softening with three exclamation marks and an apology.

Every yes you give out of guilt is an hour of your life handed to someone who did not earn it. And here is the tell: the people who get angry when you finally say no are, every time, the people who were benefiting from your never saying it.