Here in the UK I have never had to file taxes. It’s all done as PAYE. Whatever software your employer uses will work out how much you owe via your tax code each pay packet and it’s auto deducted. It’s only self employed people (maybe other types of earner, I wouldn’t know, I’m just a waged employee) who have to submit their tax forms. It’s weird other countries aren’t doing it this way.
Mate, come join us at the @actuallyautistic@a.gup.pe group on Mastodon. There are a lot of fellow autists who will be there to lend an ear if you need to vent or need some practical advice. I recommend the autistics.life instance. I have the same issue irl, people will expect me to be there when they need me, but now that I need someone on my side, they’ll happily throw me under the bus. You’re not alone, even if it’s just a few randos online.