According to the GS Admissions site, you have to have at least a 3.0 to be considered.
Don't lose hope though! I did the same thing you did while in the Navy, tried to do online classes during deployments, low GPA etc. I would recommend going the path I did: Find a community college or maybe a 4 year school nearby you, go there for 2 or 3 semesters and get your grades as sky high as you can then apply for GS.
There are two things I would keep in mind as you consider applying,
1) GS will only accept up to 60 transfer credits and 124 credits are required for your degree. If you are about to finish your Bachelors you will lose a lot of those credits.
2) If you choose a 4 year university nearby you, more then likely they will take a lot of those credits and you can get a Bachelors from a decent university vice Troy University.
Hope that helps, PM if I can help with anything