Questioning life choices

I'm a girl in her late 20's and a single mother. I'm pretty, but unsuccessful to find a serious relationship.

I work hard to earn a living to support my 6 y/o son. I work as in a grocery store and my income is just enough for a simple life.

I was originally ambitious as a kid. I used to be the top in class, until I became a hormonial teenager.

During my mid/late teens, I was addicted to love and boys. I became addicted to sex and threw all ambition out of the window.

And now,I have ended up as a drifter and a single mother. My son was conceived by accident and the boy's father left me shortly after he was born. It seems hard to find a serious relationship after becoming a mother, so I have given up.

And now, let's compare me to my elder brother. Some may argue that there are gender differences here, but I don't think that it's that relevant in today's modern society.

So about my brother:
He never gave up his ambition. He put his studies first and refused to spend time on dating as he wanted to maximize his studying time.

He followed his passion,entered an ivy league university and graduated with a M.Sc in CS.

When he started working his entry salary was already more than 2x of mine. He went all in for his career and climbed fast over 5 years and now he is earning almost 7x of what I'm earning.

He has already paid off his apartment and he is driving a brand new BMW.

However, he is still single, virgin and has never dated or even kissed a girl.

Our mother use to ask him if he is gay or what's up with the waiting.

His reply is that he will go all in on career until 30 and start his dating life after that point (he is currently 29).

Anyway,he is the reason why I am thinking and regretting my life choices.

I know that he had a hard journey while I was playing away my younger years.

What would you had chosen?
* Focus on fun and end up struggling to earn a living.
* Focus on career and have more money than you can spend, but end up as a 30 y/o virgin?