There are lots of things you could do that wouldn't involve the type of patient contact and brutal hours that go a long with an MD, nursing, etc.
You're 17, so as you look toward college, etc, doing your undergrad in Biology, or similar field would set you up well for some of my suggestions below. However, many other undergrad majors would be fine too.
1) My first recommendations would be epidemiology (study of disease) and/or public health. Both have lots of amazing applications, and could be of interest to you.
2) As was mentioned, a PhD in biology, chemistry, biophysics, biochemistry, etc. would open up doors to a career in medical research. There are several people with CF who have done this, some of whom work on CF related research. Very cool.
3) If you really wanted to work with patients, you could look into psychology (not psychiatry) - psychiatrists hold a medical degree, psychologists hold a PhD. Obviously, mental health is a very different field.
4) You could also be a pharmacist... although this might be approaching a line of too much patient contact, but there are options for career paths of pharmacists, some more clinical than others.
Obviously, all of these involve a lot of academic work, but if you are motivated to do it, and are good at time management and taking care of yourself, I would encourage you to consider it. I think there is a big difference between rigorous coursework, which is doable, and the demands of a medical residency and the risks you would be exposed to as a result.
Chris
28 m w/cf