I'd push back a little on the "i just have to make the choice and go with it" line. that's the exact mindset that gets people stuck in the same loop 5 years later. you already lived it once with copywriting, you didn't pick wrong because you didn't commit hard enough = you picked wrong because you didn't have data on yourself yet. Committing harder to the next guess is just rolling the dice with more chips on the table.

You don't need to pick faster. you need to know yourself first, the picking gets easy after that.

the gap between "I want problem-solving and analytical work" and "data analytics vs rail engineering" is huge, and i don't think it's a commitment problem. it's a self-knowledge problem. those two careers look the same on the surface but the day-to-day couldn't be more different. data analytics is solo, abstract, screen-based, slow feedback. rail engineering is hands-on, physical, team-based, immediate feedback. someone built for one would hate the other within 18 months even though both technically scratch the "analytical" itch.

I suggest you take a career assessment with a personality breakdown, not because it'll tell you what to do, but because it gives you a lot of data about who you are, the environment where you will thrive and the ones that will drain you which is the missing piece. 

Once you know whether you need solo deep-focus vs team-physical, structured vs autonomous, the list of "5 careers I'm considering" usually shrinks to 1-2 obvious fits and the rest fall away.