This is quite a delicate subject as you can imagine from the title. Backstory: small company that develop a niche software. I started ~3 years ago as a sysadmin, and while I'm good at my work if I have the time to do it correctly, I'm diagnosed with ADHD (inattentive), university is unfinished and I'm bad at following stupid orders. At first it was fun. I was scratching my head that most systems I took care of weren't updated for years. The product ran as root everywhere and software quality was, in my honest opinion, really bad (did work at university before, so no prior experience). No tests, security-holes, abysmal performance, architectural issues. But I needed the money, and was happy to have a job and had fun cleaning things up.
3 years later we got lots of new customers, new huge projects but it's still me taking care of everything. I'm now also giving user support, debugging issues in production and basically telling the developers what to fix, often I have to explain the fix itself.
It got so bad that I'm basically switching the whole 8 hours between my colleagues and trying to fix things to make it work. After work I've started to work on designing fixes to make my life easier. Unfortunately I'm a bit naïve and stubborn and I ignored some issues because I know it's useless busywork until I finish to automate that. But I've never found time for that.
Attempted to write mails with suggestions, we had meetings about it, where I made slides, explained it but nothing changed. Install is an ever changing complicated mess and I've been told early on that using docker is not a choice because the customer doesn't pay for install then.
I've told my boss that I'm way above my limits, and either I'm allowed to concentrate on automating everything with docker/prometheus/etc.pp, or I will go. We talked for 2h, and I left flabbergasted. Neither did he acknowledge that I'm putting some energy into the company everyday to keep it running, nor did he talk about my overwork, but he doubled down that I need assistance to follow the (mostly useless) tickets/lists. Every suggestion from me (automated tests, deployment via docker, finally investing some time internal tools for managing updates because I often to debug issues in production with the customer and it's 9 out of 10 times avoidable if we would run just some automated tests for each commit, etc.) were just ignored. I had the feeling he didn't understood what I was talking about. Regarding tests he told me "we have colleague xyz for that"
This would all be fine but we are in some rather big projects, like k8s deployment, clustering, likely millions of users.
I really went insane and now on sick leave to calm down. I will leave as I can't see any future there but I'm worried about some colleagues that are also suffering. I'm looking for a way to avoid contact but still act professional. I know they will ask me to fix things but at the moment I'm not feeling like I'm able to.
All that while never being sick 99% of the time, never asking for a pay rise, and often working 50h/weeks on 20h/week contract.
So I'm an idiot, but how do I stop being one and get out of this mess without damaging myself?