I definitely agree with the need to do some self-reflection/journal writing to figure out what you want to do. Finding mentors also helped me decide on a career (well, careers, I guess). It was much easier to focus on school (even the boring, easy stuff) once I had a roadmap of what I needed to do to succeed.

As for graduate/medical school, it is still possible to get into these schools after attending community college (currently working on both degrees after going that route). Good grades and high GRE/MCAT scores are essential, though, as well as good relationships with some of your professors/research mentors.

This is just a final thought, but, with a love of applied mathematics and a desire to be a doctor, have you considered MD/PhD programs for medical research? There is a newer field called biomathematics, which focuses on applying mathematics to medical phenomena, and is an area of research for some medical researchers. I've found it to be a good compromise between helping people/society and doing something that taps into my interest in mathematics...