I'm sorry I have to be the one to say this, but this isn't good. That's not to say you can't improve, because you can, just not by doing this. Please don't take this personally, because I know it can be hard dealing with harsh constructive criticism for the first time. I'm going to list your major flaws and offer suggestions to improve them. I am by no means an authoritative figure in any writing community, but I have done my fair share of writing and believe I know enough to offer my input.
I'm not saying any of this to ruin your fun. It's clear you're enjoying writing this, and you like getting positive feedback. I understand that you might not want to be the next best-selling author, you might just like writing silly stories, and there's nothing wrong with that. I just want to help you develop your ability to the point that you can write these stories, show them to people, and not be disappointed by their response.
I like to say talent is a reward, not a gift. You have to work a little to get there, but once you have it, you have it and it feels great.
Problem: Currently your character reeks of self-insert and edginess, to an almost masturbatory extent. Other characters shouldn't suddenly change or cease to exist because your new OC shows up.
Solution: If you're going to make a character based on yourself, you need to be fully aware of your biggest flaws and very in touch with your own personality. Even then, it isn't recommended you write yourself into a story because you'll never want to do bad things to yourself. Create a totally new person with flaws, but make sure they aren't
too flawed. They're supposed to be a convincing character, if you make them a blind, deaf, paralysed quadriplegic dwarf, that isn't believable or relatable. You might find it easier to base your character on one of your friends, but change them enough that they aren't a clone of Jimmy from math class.
Problem: Stories should be believable, Hanako happening to be on a walk at night, spotting somebody hanging off of the roof, and being able to get to them before they fall, all in a facility that logically should have a curfew for medical reasons, then falling asleep and ending up in the boys' dorms is not believable.
Solution: Pace yourself. Not everything that happens to your character has to be the most interesting thing anyone has ever read. Look at Harry Potter; before he went to Hogwarts he was just a kid living under the stairs, but that mattered. It gave us an idea of who he is, what his life was like before he found out he was a wizard, and how he might react to certain things. He didn't immediately start fighting Voldemort either, we saw some of his classes, his casual interactions with friends, everything that made him human. Don't show us
everything, because that gets repetitive and dull, but you need to show more than just the action points to make something interesting.
Problem: Some basic medical research should be done to make sure you understand the logistics of different disabilities. I find it hard to believe that somebody wouldn't have a glass eye in 2007, because an open eye socket is prone to infection and any creams or ointments that could prevent it would cost too much to use instead of a glass filler.
Solution: Do some research. You don't need to understand medical jargon, but you should understand what the symptoms of a condition may be, how to treat those symptoms, and any activities that somebody suffering from the condition may be unable to do. For example, if you lose a hand, you'll experience a phenomenon known as phantom limb pain, which means you feel a sharp pain in the hand you no longer have and have no way to soothe that pain. You'll also be unable to perform certain tasks, like buttoning up a shirt, without experiencing some problems. Disabilities are, as morbid as it sounds, very fascinating things to research.
Problem: Your character doesn't have a Japanese name, but speaks fluent Japanese and is attending a Japanese school for the disabled without any reason for being there other than "I'm disabled and Yamaku."
Solution: Pick a Japanese name. It's a simple solution, but it makes more sense for Kenichi Watanabe from Sendai to attend Yamaku than Michael Fox from Boston. If you want to put more time into designing an interesting character, you'll need to know about Japanese culture. Which is my next point.
Problem: You should probably have a very basic understanding of Japanese school life and culture. Nothing too fancy, just enough that you can create the sense that the story takes place in Japan without saying so directly.
Solution: Do some research. Details like calling friends by their first name, but acquaintances by their surname. Japanese society has a concept called amae, which is fairly complicated so I'll just link
this Tofugu article if you want to read it. It's basically about senpai-kouhai relationships, which you may be somewhat familiar with if you watch anime or read manga.
Problem: Not evident yet, but I imagine it would pop up pretty quickly. The sequence of events in Katawa Shoujo.
Solution: You should understand the KS timeline, Hisao's first day at Yamaku is Monday the 4th of June, 2007 and the festival at the end of Act One is on the Sunday of that week. I'll leave it up to you to learn the order of other events from the VN, should you choose to use them.
Problem: Your characters are currently nothing like their canon depictions. There's more to Hanako than scars, burns, and shyness.
Solution: Read Hanako's route again, and take notes on how she reacts to certain things, who her supports are, what her speech patterns are like, etc. You can also read other Hanako fan fiction for this, as there are some fairly accurate depictions of her character on the forums. This applies to every character you plan on using.
Also take note of
this image. The characters in class 3-3 (not 3-1) have names and disabilities, and are often used by other writers on the forums, so it's probably best not to make one completely disappear for the purposes of introducing somebody new. Other classes exist, if you don't want to use Hisao, and there are still ways to
Problem: You're currently inexperienced and attempting a route.
Solution: There is no clear solution to this other than to practise with shorter works first. A route is an
enormous project, one you aren't ready for yet. I know this because I attempted one as one of my first projects here. I had relative success, finishing my first act and the first chapter of act two before cancelling, but I'm a rare case.
Compare a route to a novel, because they are roughly the same length in most significant cases. You aren't going to try to write a novel before you write a short story, that's a ridiculous concept. Similarly, you won't write a half-hour long symphony before writing a basic chord progression in music. I highly recommend you convert this thread into a one-shot archive, which I'm sure you have seen on these very forums, and practise writing short stories with your favourite characters. This will help you understand the fundamentals of writing, people will give you helpful feedback more often, and you'll start feeling much better about your own work as you develop.
None of this post is intended to discourage you. I was in your situation in 2013 when I started work on my Miki route. I had never written anything longer than 2,500 words and I didn't really have a plan, I just kind of posted and let it grow from there. The forums were more active two years ago, so I got the feedback I needed from multiple people and now I feel pretty comfortable in my writing ability. It's not spectacular, but I like to think I can write a pretty good story these days. I look back at my Miki route and think it was pretty bad, and you'll probably do the same with whatever work you do now, but that's all part of the process. So, please, don't stop writing, it's a beautiful thing to be able to create a story and draw a wide range of emotions from your readers, to build entire universes in your head and get a different perspective on your own life in the process, to inspire people to do something they've never considered doing before, and fan fiction is a great place to get a grasp of how things work. Talent is a reward that everyone can get, and you're one of the lucky ones working for it instead of wishing on a star.
