bloooop
As for actual, true-ass advice though... I can say your overwhelming fear of entering adulthood is a good start because the sooner you can get rid of that bullshit-ass teenager romanticized stardust-in-the-eyes fuckery about adulthood the better. The worst thing you could do is enter adulthood with all these stupid fucking notions of what adulthood is and how you should conform to that shit.
The tax-paying, laundry and other things are kinda scary, true 'nuff but it's not as scary literally, when you work out a schedule to do them and actually do them. You'll learn which ones you can put off for a day (laundry full of non-essential clothes, i.e. house clothes/pajamas), which ones are better done far in advanced (taxes & bill payments) and which ones you can do because you miraculously have some free time to kill (dirty dishes in the sink or a carpet to vaccuum).
Now, I read what you were scared about and I'm on a good, solid 99.9% certainty that a lot of it stems from this teenage fear of not being able to adult "right". No one here was lying about learning to do taxes, balance checkbooks will get easier with repetition, if you're bad at math it's just a nuisance rather that a horror story. A lot of adults still can't do that shit right, honest talk-- it's why there's actual professions that are there to help people figure this shit out. Auditors, tax lawyers, legit folk who knew there were gonna be motherfuckers who don't know how to take care of that shit.
And that's okay.
One of the biggest lies teenagers ingest and repeat amongst themselves about adulthood is that your ass needa know everything right off the bat.
FALSE-ASS LIES. First'n foremost. Somebody lied on that shit, and a whole bunch of other fuckasses kept it going. Get rid of that thought, Thom.
On that note, however, I wanna tell your young butt something right thefuck now: Disabuse yourself of anything lookin' close to "I am/You are an adult, I should/shouldn't _______."
FUCK. THAT. BUNK.
Try not to do and try not to fuck with anyone who even smells like they busy themselves with what they think an adult does, doesn't, should or shouldn't. Those fucks are too preoccupied with looking like adults rather than being adults. You know that fear you shared with us about your mother? She's not a bad adult. She's an adult who's fighting with depression, and that is hard in and of itself. That's depression on top of doing things that need to be done whether or not she's feeling up to it, on top of folk trying to act like their shit don't stink and feel like they have something meaningful to say about how she handles her business. With what you've told, there IS a problem in our (U.S.) society where an adult isn't allowed to have shit in their life that makes adulthood "hard". Too much of that bootstrap shenanigans. The other folks you mentioned, who've had shit get "harder, and harder" on them... well, there's the shit that makes it hard but what really does not help is this sentiment we all have that's echoed throughout your first post that adults "should" always be on top of their game.
Another ginormous lie that teenagers ingest and pass around to each other about adulthood is that if you fuck up or you fuck up and don't recover quickly enough it is game-over.
LIES ON LIES ON LIES ON LIES ON LIES.
... But I get it, you've seen folk crash and burn on their shit and it's scary as fuck. What tends to stop folk is that little annoying voice saying "This 'shouldn't' have been a problem, I can't believe it. You failed on this. There's nothing now. You failed. You failed. You failed."
Bull. Roar.
Fucking up by, for example, saying some racist fucking shit in which your employer finds out about and consequently fires your ass is not the same as missing a payment and now you have to do some extra paperwork and wait a week or two for your light to come back on. Now, I'm gonna say something that sounds really scary but you gotta hear me out on it, okay?
Life does not give a slippery shit or a flying fuck about your successes or your failures. It's going to keep going with or without you being ready.
Seems horrifying, doesn't it? It's not. Not really. Now, what I mean by this is (without entertaining ridiculously extreme examples like inadvertently participating in genocide) there is no fucking up so badly that you can't bounce back from it. Lemme get a little Deepak Chopra on you real quick:
"If you obsess over whether you are making the right decision, you are basically assuming that the universe will reward you for one thing and punish you for another.
The universe has no fixed agenda. Once you make any decision, it works around that decision. There is no right or wrong, only a series of possibilities that shift with each thought, feeling, and action that you experience."
Now, the original quote is a bit longer but this was the most relevant piece. Adulthood doesn't grant you clairvoyancy. You know that that extra slice of pizza is gonna tip you over the edge and you'll spend a couple of hours as an uncomfortable human beach ball but you can't know if taking the job at the call center is gonna be better than taking the job at the local mall's security force. I see a little bit of myself in you right now Thom, especially when you let out that you want to learn how to do shit correctly the first time. That's a good mindset, not a good practice. You might fuck up in recreating whatever shit you just learned, and I'm telling you to unclench and allow yourself the inevitable fuck up. Other people do not have the time to be holding your hand through something, this is the literalest of literal things. Like, you're scared that when you get a job and then you learn to do the register you'll fuck up someone's money or cost the company a huge sum of money that'l come out of your paycheck. You definitely do not want that, neither does the company.
But what the company knows that you don't is... that you're new. You're learning. It's going to take time. But I know, "Koori, Koori! Okay, you say that, but what if... what if, what if I fuck up so badly I'm fired on the spot!"
brb ugly laughing
Okay, first thefuck of all, I said unclench. The likelihood of you fucking up SO ENTIRELY BADLY that you are fired on the spot is pretty goddamn small. I'm serious about unclenching, the more you clench up is the less information you're taking in on how to do your job. You literally need to relax, pay attention when someone's teaching you and, I know high school didn't really prepare you kids right but if you need something clarified...
ASK FOR CLARIFICATION THE MINUTE YOU DO NOT GET IT.
While your supervisor doesn't have time to hold your hand through everything, what they'll appreciate is you nipping any future hiccups in the bud during training. It also looks good, they'll see you as as an employee dedicated to the job, wanting to know how to keep shit running smooth. Shit, take notes if you have to. Fuck any fellow trainees tryin' to side eye you with your little notepad and pencil. You needa learn your shit, and if you feel like you gotta write shit down so you can look at it and properly digest the information, then you fucking do it. Get your shit right, because those judgemental little assholes aren't gonna get your paycheck, you are so handle your business. Don't fuck with kids who'll try to one-up you about that kind of shit. You do what you need to.
That's what I mean by as soon as you sniff 'em out, don't fuck with the kids preoccupied with looking like adults. Fuck those kids. You'll know who they are when they say shit like "Why don't you just get a car?" Those kids are nonsense and have no concept of money. Or literally how shit works. Boromir's quote about not simply walking into Mordor is applicable in so many other parts of life that's not even on Middle Earth.
Koori is tl;dr:
YOU ARE ALLOWED TO FUCK UP
YOU ARE ALLOWED TO FUCK UP
YOU ARE ALLOWED TO FUCK UP
YOU ARE ALLOWED TO FUCK UP
YOU ARE ALLOWED TO FUCK UP
YOU ARE ALLOWED TO FUCK UP
YOU ARE ALLOWED TO FUCK UP
YOU ARE ALLOWED TO FUCK UP
EDIT: Oh shit, I forgot to put the other part you asked for. The bright side to being an adult... is getting to decide what that means for you.
The taxes'n bill paying etc. is non-negotiable tho, that shit you have to do regardless. sorry booboo