There are many careers in medicine in the US, all of which pay well and have good prospects: DO, PA, NP…
Look into those. Make them your Plan B and C.
They’ll require a lot of experience (like med school) so look into becoming an EMT or CNA to get hours (+ you’ll get paid).
Don’t wait till you get a B - go to the “tutoring” or “science center” (or whatever it’s called at your school) and review even the first week’s material. The goal isn’t to pass, but to be among the top students. It’s a different mindset and you have to ajust. Make it a habit to go to Office Hours weekly and ask questions (either because you didn’t understand, or because you found a point especially interesting).
Make a balanced schedule: 1 difficult class, 2 medium classes, 2 easy ones. If chemistry is especially difficult for you, it’ll be your “difficult” class.