If your cumulative GPA is a 2.9-3, your chances are not very good, especially with a 26ACT. Those are both WELL below average.
You may have a shot a the prep-school. The application for USAFA doubles as the P-school application. You may also get a Falcon Foundation scholarship to do a year of prep at a different school. Some people do a year of college to boost their academics, then reapply.