+ Use a 'tape recorder' to capture your thoughts, have someone else transcribe it...or a machine...your future self might also be that other person.
+ You are the only person who judges you based on typing accuracy. Everybody else is focused on worrying about their analogous self judged flaws.
+ Practice writing using free writing. Both by hand and typed. Because writing is hard.
+ The writing in your question is perfectly fine. That's probably because it took you a long time. Time spent working on something written strongly correlates with the quality of the work.
+ Join a community of writers...or another one since part of what HN is, is a community of writers.
+ In the end, this is a bit of an XY problem. What you want is to write. The way to write is to write. Writing is always a struggle. Better typing comes with experience. Better writing doesn't come from better typing.
+ Your writing is fine and that's all anyone else will care about.
+ I feel I spent way to long writing this. That's ok. I have become used to the feeling.
Finally after all that on my end another suggestion:
Buy a mechanical typewriter. They are mostly distraction free (except for mechanical tinkering). One of the good parts for me is how a mechanical typewriter forces me to deal with typing errors...no matter what I do, they still live on the page in some form even with correction tape...so I over strike or strike out or ignore.
Why I suggest this for you is a mechanical typewriter will always produce imperfection...and that force hones judgment about what is and isn't important.