All i can say is do research, as well as shadow as much as you can. That way you get " a day in the life" experience. Also for the CRNA route you need to become a nurse first as well as practice for 1 year in ICU for quite a few schools.
I agree that you should shadow in all 3 of these fields. But you can also see which career you would prefer another way. Like, are you more interested in science and human movement (PT) or psychological processes and student's daily problems (school psych)? Those are two very different careers, so although you may like both, you have to dig deep and see which career has the core that you really love.