Career/Life Guidance?

I finished university 2 years ago, and now I'm in a slightly existential crisis as I'm not sure what to do further or how to channel my ambition and energy. Currently, I'm in a back-office role in Asset Management.

To begin with, I wasn't a stellar student and in my teenage years, I didn't have big expectations for myself, just thought about ending school as soon as I can, finding a construction job and just having a mediocre life. But I experienced a catalyst event in my last year of high school that put me on the self-improvement path.

During my last years, I was so much into self-improvement and reading, that now looking back, I can't recognize myself. I've read a lot of philosophy, especially stoicism, self-thaught myself maths from 0, I've read around ~ 300 books, learned 2 foreign languages, and generally developed myself in other areas such as relationships, communication, public speaking, etc., but despite this huge progression and improvement, things such as low high school grades, a mediocre university, and mediocre grades, are things from the past that I still need to disclose on applications even if those reflect an opposite image of my current self.

I was seriously thinking to pursue a 2nd UG degree at an Ivy just to change my life and don't let my past failures prevent me from getting the opportunities that I feel I deserve down the road, but my high school GPA is a shame.

I also gave some thoughts about the idea of getting into tech or start-ups because those tend to be more meritocratic than corporate jobs, but discussing technology, IT, and innovation isn't something that resonates with me. I'm more the "give it to me and I'll execute it" with some touch of seriousness type of guy, so I'm contemplating more traditional career paths (IB/PE/HF/Consulting).

Starting a business is something that I'm planning to do down the road, but I want to gain more experience, to begin with. I found it interesting reading about finance during those past years. It started years ago with some generic personal finance books like Beating the Street and others, but then I grabbed some more technical things that actually develop some expertise and skills and I've gone through Rosenbaum, Moyer, Linneman, etc. and I enjoyed them. I would like to specialize in that, but again, no one is interested in my resume.

Where should I go from here?

Thanks in advance for any advice/fresh perspective on my situation. Appreciate it.