I highly recommend this combination! It really opens up a variety of opportunities you have available to you, depending on your interests. Both majors are pretty broad, which can be good if you're unsure what exactly you want to pursue after college.
I can personally speak to the mathematics portion of your question for sure, and give you some recommendations from my experience. To give you a bit of background, I majored in Mathematics and Economics because I had no idea what to do after college. I chose *not* to major in computer science on purpose (I considered it), because I knew I was a people person -- I enjoy talking to people rather than talking to computers and would absolutely hate if my job didn't involve talking to a variety of people everyday. But, I have encountered many opportunities where I could have used a computer science degree, even if it wasn't for me.
Here are some professions that I can think of that would be a great match for you, and a quick explanation on why.
- Data science: This profession can open you up to many different industries (healthcare, oil/gas, technology, finance, etc.)! There can be a ton of programming involved in this profession (Python, R, etc), which your computer science major can greatly help with. For the math piece, this field will likely be more of a statistics form rather than pure math (theorems, algorithms, etc).
- Security Engineer: I work in security, and work closely with this role. From my experience, this profession involves a decent amount of programming, which ties into the computer science degree. However, this role is really interesting in that it touches on some mathematics theory and algorithms, especially when it comes to secrets and authorizations. If that doesn't make sense to you, no worries. Think about passwords -- having a math major can help you think through security topics like "how long does a password need to be in order for it to be secure enough that it is very difficult to crack?" It's a very interesting field, and I was very drawn into security when I got introduced to it.
- Specialty roles: There are a ton of specialty roles out there that both majors would help with. Take, for example, one role that I interviewed for at Google. The role involved writing code (computer science major would help) to establish algorithms (math major would help) to identify spam in Google search.
- Engineering roles in general, but especially computer engineering: Depending on the engineering role you apply for (which a computer science major will definitely help with), mathematics can also really help! Mathematics involves a different kind of thinking that other majors do not offer. A lot of computer algorithms are based on math theory, so having a math background can help you gain a deeper understanding in computer science and how it all works, leading you to be more successful in a variety of computer engineering roles.
The opportunities are endless with both a computer science and a mathematics major! You shouldn't feel "stuck" or nervous about not being able to find a job with this combination of dual majors. Hope my answer helps! :)