For me, it's like solving puzzles all day.

I get that it is demanding, and that it may drain you, but why?

What would your brain feel like if you were told to solve high level math problems from 8AM - 5PM? That's why it's draining, and why it's such a high paying job. Working extended hours is common as well. You don't have much time to spend with family or friends, so I have to make sure to make the most of my weekends. I have a list of goals to meet within a deadline everyday, and they aren't mundane tasks. We follow a strict schedule so that we can ensure we can release an update about once a month.

Aren't all your tools essentially there?

The world of computer science is very broad. You have numerous languages and you'll never feel like you truly "know" a language inside out. Computer science languages are not extremely difficult to learn, but thinking of how to use it, and understanding data structures/discrete math, is very important. That's what interview questions are based on.

you're more often than not working with a team?

It is a team effort, but it's not like we work side by side constantly. We have our own tasks to do, that we will update each other on every few hours.

Computer science is essentially a mathematics major. I highly suggest you try to take various summer classes at a community college if you can, one of which is a Java or C++ introductory course. From your questions, it sounds like you don't have much experience in it, and that you're underestimating it. I understand being under peer pressure during senior year, I initially chose biochemistry as my major because everyone else in honors did. If you're extremely undecided about what you want to do, focus on completing your GE classes during your first year.