I'm just completely useless with money, I'm skilled and earn well but I'm always broke

As the title suggests, I'm just always broke.

It probably isn't related but is perhaps worth mentioning that I'm an autist so I sometimes get confused by things everyone else just does as second nature.
I don't know how to survive... I feel like I can barely function.
My question, really, is how the hell does everyone do it?
I make about 3k per month but I never have any money... I don't go out drinking, I don't eat out at restaurants, I cook meals for myself and I try to buy the cheapest stuff from the reduced section. I don't understand how people are managing, I am just... broke.
I am an engineer and I have had ideas to maybe start a side business repairing computers or something, I find that stuff really easy... I can fix just about anything tech related from like basic stuff up to like component level repair on bespoke electronics... I have the skills that would make me money, I just don't get how anyone does it, I've advertised and I never get a single call. Maybe I'm advertising in the wrong places idk.

Backstory out there, my main question then is like ... how do you use your skills to generate income in the UK?
I have the skills I just don't have a financial mind, I am completely useless at that kind of thing