So yeah, while it is totally fair to just end a project you no longer love or have any interest in (as much as I adore the later parts of dragonball, like cell and whatnot, toriyama probably should have ended it when he wanted to for his own sake), its important to make sure you're not doing it out of low self-esteem.
Don't give up! There are times you won't be confident with your writing - whether it's the actual language or the story itself - but I think it's worth it to push through and keep writing anyway, because at some point you'll break through and everything will get better. You can only get better at writing by writing, you know?
I'm here on Royal Road with the most pathetic excuse for a fantasy romance. I've been writing confidently for many years and I have my own writing style down, but fantasy is a real challenge for me because I'm horrifyingly bad at writing magic anything and my story is a flaming pile of trash, but I'm enjoying writing it at least, and that's what matters. Try not to compare yourself to other writers, you have to do it at your own pace. Remember: Your story is worth telling!
English is my second language, and I had many problems when I started writing in it. It got a bit better, but it's a process. It doesn't happen overnight. Just chill and keep writing, my man.