I'm a perfectionist and I have a B in English

I know that a B is still passing, but English is my best subject and I can’t believe that I have a B. I got my grade back on my first essay this semester and the result of it was an 89%. I’m so disappointed in myself and I could push myself a lot harder than I’m pushing myself right now. I’m trying not to beat myself up like I am right now and I know that not all of my grades are going to be perfect, but I should be doing better than I am right now. I completed a quiz and I received an 80%. Am I really too much of a perfectionist right now over my grades?

Yes.

I knew it. I’m way too hard on myself on this.

Yup. Being a perfectionist makes life much harder than it has to be.

The way I use to deal with this is to figure out what is causing you to not perform as well as you think you could.

Did you not study for the quiz? Did you focus too much on things that ended up not being tested? Was it a matter of getting used to how your teacher asks questions?

Same for the essay. What made you lose points? How can you fix it for the future?

If you can figure out what’s lacking and do your best to address it, then either a) your grade will improve, or b) you’ll have done all you could do. Either outcome is better (at least in my mind) to feeling like you could have done more but didn’t.