Overwhelmed and stressed. CRA is angry with me. Don't know what to do.

I come from a family of mentally ill street people, drug addicts, convicts, etc., and I had no "real adults" in my life until I turned like 30. So when it came to taxes and business practices, I was completely on my own with zero mentorship or guidance. I've always had day jobs, but I've always been an artist. Learning that as an artist I could be writing off supplies and services intrigued me. I've always been super poor so any financial leg up sounded like a good thing. I registered as a business and I bought Quickbooks Self-Employed.

Things get extremely complicated when I find out the hard way that the most recent day job I had for five years "technically" wasn't a job, but a contractor position, and I should have been taxing myself the whole time. I didn't know that this was a thing. I always just knew employers as the ones who took care of tax stuff and I get to spend whatever I'm given. This has absolutely decimated me financially. The amount of debt I've allegedly accrued to the CRA is insane (for me).

As someone with a couple neurodivergencies/learning disabilities, Quickbooks and the very nature of how taxes work is extremely overwhelming to me. I feel like the way a lot of things are set up in Quickbooks don't make a lot of sense (I will spare listing the dozens of contradictory UI issues I've noticed that limit functionality). I think I've been categorizing things wrong for years and as someone who doesn't make a lot of money, it doesn't add up to me that I owe as much as the CRA claims I owe.

I've had three accountants now and each one of them has made me feel like a burden to them with my questions about these things and the strange nature of my work (sole proprietor of a art/service business) and they pretty much do nothing outside of filing on my behalf and charging me for it. Turns out my most recent accountant didn't even file my personal taxes for 2021 or my business taxes for 2022, so I thought hell it's time I do this myself. The person handling my issues at the CRA is a lovely, patient, understanding and sympathetic human. She recommended I tried filing on my own. I used Wealthsimple's tax thing and sent off 2021's personal. It wasn't long before another department of the CRA hit me up to hold me over the coals for how wrong apparently I filed and now I'm back at square one feeling overwhelmed, helpless and stressed. I'm literally losing sleep about how much money I'm going to be paying off for what seems like decades to the CRA and though it doesn't seem correct I am at a loss of what to do and I am struggling for an answer or a direction.

I've heard of accountants that are Quickbooks Proadvisors - are they well-versed enough in Quickbooks to set me up in a way that makes more sense and potentially undo any mistakes I've made in the past? I feel like I need to refile as far back as 2018 and the accountant fees alone in doing that make me scared.

Any and all advice, guidance, pointers or wisdom is extremely appreciated.

I wish they taught this shit in schools.