Here is a useful self-help exercise about saying No. It is from Gabor Maté's Wisdom of Trauma webinars on Zoom in Oct 2021 at www.scienceandnonduality.com.
I wrote this up from his words of wisdom. It a six-part exercise that you can do if you have trouble saying No. (And it's not self-accusation, it's self-inquiry.)
- When in your life is it difficult to say No? (When is there a No that wants to be said but you don't say it?)