Quitting is fine. Just be honest about whether you’re done with it or scared of it.

Stopping is a legitimate choice and not every quit needs defending. What is worth knowing is which of the two this is, because being finished with something and being frightened of it feel nearly identical from inside and lead somewhere very different afterward. One closes cleanly. The other tends to follow you into the next thing.

Test it with a question: if you were certain you would do well, would you still stop. A yes means you are done, and that is fine. A no means the fear is deciding, which is worth one more honest attempt first.