I'm bad at writing

Nobody told me that I’m bad at writing, I guess. I probably failed my English GCSEs because my hands suck. But I did fail.

Does that mean my writing is bad? How do you evaluate it. I’ve been told that I’m bad at English. Which is weird. I’m highly eloquent and was born hyperlexic.

What’s good writing?

Pacing?
Using the correct words?
Conveying a feeling?

What isn’t good writing? Can you show me an example of bad writing?