Don't worry too much about boosting your overall GPA. First of all, yeah it's not great, but it is enough to be considered at most schools and it WILL go up if you get a 4.0 in all of your prereqs, even if it is only a slight improvement. Second of all, a 4.0 in all prereqs will most certainly be looked upon very favorably by most schools, regardless of your overall GPA, which by the time you're done acing all these classes, will be higher than it is now anyway. Don't stress about the GPA, just strengthen your overall application.
Your goals for now should be:
1. Ace those classes as planned.
2. Get substantial volunteer/observation hours in different settings.
3. Do well on the GRE.
4. Form relationships with your professors and PTs you work with to get strong letters of recommendation.
5. Write yourself a great essay for the PTCAS application.
My undergrad GPA was 2.9 from a long time ago, and I only had two prereqs left to take to prove I'm a better student now. Got an A in anatomy (currently taking physio) but that A barely made a dent in my 2.9. That didn't stop me from getting an interview at my school of choice. For my situation (i.e. for my school of choice) doing well on the GRE really helped make up for that terribly GPA.
Good luck!