It sounds to me is that you’re panicking because you feel like you are behind. You started CS “late in the game” (though how freshman or even sophomore year of college can be late in the game, I have no idea) so you feel like you’ll never be good at it. It’s okay to struggle in something. It’s new. You’ll get better at it, especially if you like it. It’s completely fair if you don’t want to spend your entire day in front of a computer, but keep in mind, that in the technology age, every doctor I know (and I work in healthcare) spends half of their day in front of a computer.
You haven’t been doing pre-med classes and activities so you feel like it’s “too late” to do it. Relax. It’s not too late. There will always be people who seem like they are “ahead” of you. You will always have to compete with others, especially if you want to go to medical school where the competition never really stops. There will always be people who seem more qualified. That’s just a fact of life. And you’re kidding yourself if you don’t think that physicians have to keep learning and memorizing things. Medicine is always changing, and the best doctors have to keep up with all of these changes. It’s not as insane as medical school because you have a basis to build off of, but there will always be something you don’t know.
Here’s what I would do, if I were you. I would drop the econ major, and I would use that space to take some pre-med prerequisite courses. I would look at both CS and pre-med type internships/activities/organizations because I wouldn’t throw a subject I love out the window just because I’m not instantly amazing at it. I would try to volunteer in a hospital and shadow docs to see if that’s what I really wanted to do. If I realized that medicine was what I really wanted to do, I would look further into applying to medical school and do additional things that would help my application. Like another poster said, the worst case scenario is that you don’t feel ready to apply your senior year and you take a gap year. Not a big deal at all, and in fact, can make you a much stronger candidate than if you rush to apply your senior year. Medical school is not going anywhere. If you really want to be a doctor, then you will find a way to make it happen. If you don’t want to find a way, then maybe you don’t really want to be a doctor, and that’s still okay.