Resign in first month and go to B-School?

Hi All, I am in a tricky situation (thanks to my bad decisions).

TLDR: I've just started a new job but I don't like it. I also have an offer from a top b school for a master's program.

Should I just quit the new job and go to school? I wanted to decline the master's because it's expensive (by European standards) and I don't have the money, that's why I started this new job.

Not to mention that it would look really bad if I have a job on my resume where I didn't even last the probation period... Or should I just leave that out from the CV as no one will care about that 1-2 months anyway if I go back to school by the end of the summer?

Some background for those who like to read:

I have a bachelor's degree in econ from a no-name uni (the best in my country, not even top 500 worldwide), so sooner or later I will want to do a master's degree, but I am not even sure what subject (prob. econ instead of finance and I was accepted to a finance program now) The admission process is quite rigorous and it's hard to get into this one so it would be a shame to decline it. (Usually, top 1 or 2 people get into this from my whole country in a year!)

However, I'm still not sure what I want to do so spending that much money (what I don't even have) seems like a gamble to me. However, this new job was a really bad decision and a low-key attempt to sabotage myself so I am clueless about what to do now.  If I don't consider the money, uni might be a better option as I will have more opportunities to pivot my career and I can still apply to grad programs. Doing a master's is also important for me and the more I wait with it the harder it is to leave the job and go back to uni.

Honestly, I am not interested in big money, the important things for me are that I enjoy what I do, have fun in the process, earn decently well, am surrounded by inspiring and good people, and do something good for the world (haha wrong industry for that...) Probably something at the intersection of econ and finance at a non-profit GO or NGO (where the competition can be as high as for an IB or PE role). I would be also interested in doing a PhD later on in my career so a master's is a must-have, and I don't see the point of wasting another year doing a job I don't like.

And yes, I know, those bs folks will eat me for breakfast with my indecisiveness.

Thanks for reading and any advice is highly appreciated!