Your supervisor incorrectly blames you for a failed project during a meeting. You want her to understand how much work you put into the project.

I ask for permission to explain that my supervisor is incorrect. I explain my work politely and show how this "failure" does not exist.

Explanation:

At this point, the important thing is to remain calm and in control. Your supervisor, like everyone else, is likely to get confused and blame people for things that are not their fault, or even find fault that does not exist.

In that case, you should wait for him to finish speaking, ask for permission to speak and explain how you did your job and show how your supervisor is wrong about the conclusion he made. This must be done calmly and politely, always maintaining respect.

cutting out negative people, changing their diets, exercising, taking off days from work or school, etc