I read your bio.
Don't worry, I've got a story with four chapters and two prologues (And one author's note), I've got two drafts as well (One for chapter five and one for the plot of the start of the Sports Festival).
It's taking me a while to finish it compared to my other chapters (I got them done in at most 3 days), because it's taking me about a week to even get personalities straight. I always worry about how accurate the personalities are rather than how often I get the chapters done. When it comes to canon writing, I prefer quality over quantity. I have collaborated a bit with someone else due to how lopsided I am with the character personalities.
So don't worry about how often you get chapters out, it'll be fine.
It also helps you build up your writing skills so you're able to write faster (E.g. I can write about 1000 words in a day without a break and with a good plot, I used to only do like 200-400 a day).
Just keep trying.
~Your local cursed image dealer