I need a career change - good careers that don't need uni?

I feel badly in need of a career change. Can anyone suggest any stimulating careers that don't need a degree or maths above A level?

I got an HND in Biology and Chemistry from college when I left school and passed with As years ago (pre ASD diagnosis) but my career has been a disaster. I've tried to be a lab technician for the last 3 years and realised it's not for me (it's initially interesting, then the low level science doesn't stimulate me enough and I found myself looking at the scientists and wanting to do what they did). I'm fiercely intelligent and need something that can make me think and use my knowledge, or something where I can concentrate solely on the task for hours. I want to make a difference and get a 'job well done' feeling at the end of the day.

I also need something well paid, because my relationship with my parents isn't good so I don't want to move back with them. 

I started a degree this autumn and was really enjoying it until a traumatic thing happened which made me lose a month of teaching. The uni were great but I was unable to catch up properly and I've failed my first 2 exams as a result. 

And as well as a pandemic and autism diagnosis, I've been through almost non stop trauma these last few years. I'm aware I might get comments telling me to 'suck it up buttercup' more or less but I've been 'sucking it up' for years now, frankly!

I'm exhausted. 

I'm looking at being a train driver currently because that seems a really cool job - like, I'd love to drive a train! I've always enjoyed travel and the railways, and being alone in the cab all day is quite appealing to me...

I'm also looking at the navy as mucking about with machines, boats and weapons systems and working with my hands would be fun - but I hate being shouted at and worry about bullying.

I've always had a talent for writing. I've always enjoyed doing it and if I could get an office team with good office politics it could be good, I just don't know what's out there.

Friends have told me I interact well with customers. 

I also have a talent for art - but are there any careers that are stable income out there??

Any career change ideas would be fantastic!