To the OP:
Welcome to PF forums!
If you decide to pursue a degree in mathematics, there are numerous options that are available to you in terms of careers, besides finance. One option that is available to you (especially if you mix your math courses with courses in probability, statistics, and some programming or computer science courses) would be to work in statistics or data science (especially after completing a masters degree in that field).
For example, I'm a statistician working in the pharmaceutical, biotechnology, and health care fields for the past 16 years, after completing my Bsc in mathematics and a Msc in statistics. Among my responsibilities include addressing the design and analysis of clinical trials for various therapeutic areas, and doing retrospective analyses of past clinical trials of observational studies related to medical treatments.
Another option that is open for you, especially if you enjoy programming, would be to work in software development/IT/tech work. Mathematics often is a natural fit with computer science (much of theoretical CS is pretty much pure math), and many people who double major in such fields often work in the tech sector working in places like Google, Facebook, IBM, etc.
Yet another burgeoning field is in the field of data privacy/cyber-security. We are living in a time where the Internet is reaching ever further corners into our daily lives and our economies, which makes it ever more systems vulnerable to hacking. Thus making cyber-security more important than ever. People with strong backgrounds in mathematics have played important roles in developing strong encryption schemes to strengthen such securities, and I see more opportunities opening in such areas (again, if you combine your math degree with appropriate courses in CS).
Those are just a few of the options or areas that are open to you if you decide to pursue a degree in math (I also did not include options like teaching, or further graduate studies). Hope this gives you a taste of some of the possibilities open for you.