Have you considered the military? Your background sounds a lot like mine and this was the path I ended up taking and am really happy I did. With a degree you can commission as an officer, you’ll learn a lot of discipline, time management and other really good habits.
It's definitely not the life for me. Extremely harsh living conditions, idiotic bosses, chain-of-command, blind following of orders, zero place for innovation, intellectualism, or individuality- these are not really my cup of tea.
He went simply because he had no other means. His family is extremely poor, and unless he wanted to be poor like them as well- he went. While he is smart, he is no intellectual.
NCO in the Army is a vastly different situation than a commissioned officer in any branch, and each workplace is going to differ in terms of idiotic bosses, harsh environment, intellectualism, and tolerance for innovation and invididuality. The rest of your items (chain-of-command, blind following of orders) are going to be present in some form everywhere in life, and you're welcome to push back on those if you're careful about how you do it.
Sounds to me like when you say both that you want to learn discipline while also saying certain things are not your cup of tea, one of the areas of mentation you may want to work on is "the ability to experience, tolerate, and overcome discomfort". Discipline may even be described as that ability, in part.
Not saying you absolutely need to join any military service to get that, but there are few other circumstances where you have no real option of quitting once you've committed to a certain duration of obligation.
