Am I too old and what are my odds of breaking into finance and having some success on the way?

I suppose I should give a bit of background of how I ended up where I am and why I’m here asking for advice. I do apologise if this ends up being longer than I intended but I will do my best to keep it as brief as possible, where possible.

I’ll start by saying that I’m originally from one of the Baltic states (Eastern/Northen Europe). Moved to London when I was 16, went to school, did my obscure and highly impractical A-levels (High School equiv. in U.S.), didn’t to to university as I had no idea what I wanted to do and most definitely didn’t want to amass substantial student debts.

Since then I’ve been working various low level jobs, the type of jobs that make you question whether it is all that life has to offer, however, I have been lucky enough to meet some interesting and kind people along the way so it’s not all negative.

Despite being quite curious and questioning the point of me being on this planet since I was a kid, 26 was the age when it really hit me and I was wondering if I want to spend the rest of my life doing jobs I don’t enjoy, jobs that barely allow one to get by, jobs that require 0 thought and provide 0 room for growth.

I’ve always had interest in business, have read a number of books on investing (starting with the basic stuff like Intelligent investor, Common stocks uncommon profits, why stocks go up and down,to more advanced textbooks on HF’s, PE, Real estate investing and even read the whole McKinsey Valuation textbook). I thought I might give finance a try.

Paradoxically my newfound enthusiasm to do something about my life was flushed down by a wave of self doubt and this idea that I’m an idiot, a failure. “I’m fluent in 3 languages, pretty literate, hard working yet I’m stuck doing nothing career wise, no degree. How could I have not capitalised on the skills I possessed…I must be intellectually handicapped”. This though process fucked me up for good 2 years during which I was pretty much paralysed and had to seek help from a psychologist.

Luckily met a psychologist who guided me in the right direction, opened my eyes to the fact that I don’t lack intelligence. I always thought that I’m missing something in the brain department but turns out I scored above 99.99th percentile on this IQ test that I was given. It’s not that I put too much faith into these tests as a predictor of one’s potential, also the test only consisted on non verbal reasoning, however, it did bring tears to my eyes, gave me a sense of validation and the emotional relief I needed to move on.

I’m 29 now and since then I’ve been actively teaching myself A-Level mathematics & further mathematics (pre college - potentially 1st yr college maths for the readers across the pond) and I’m hoping to do a degree in either Computer Science, Economics, Mathematics or some kind of combination of the two or three.

Given my whole story and current circumstances, I would like to return to the title of this topic and ask for some advice, perhaps some direction as to what is realistic and unrealistic for someone like me. I’m an optimist, however, such scenarios call for a realistic assessment.
Any advice, constructive criticism or both at the same time are welcome. Perhaps some of you have overcome certain obstacles on your way to where you are now so it would be great to hear from you.

Once again apologies for the lengthy read, I did try to compress it as much as I could and thank you in advance for any advice.