John: Personally I would advise you to finish school. In 1963 I was 23 years old and had completed 3 1/2 years of college when I enlisted with the intention of finishing school in the service. I got my degree in 1989.
Part of the problem is your major. I was a chem major and most of what I learned became obsolete rapidly making many of my classes invalid. Math is similar. They teach things in grammer school I learned in college. There are many roads in the military, including SF which require college.
Just my .02. I ain't your Dad and am really not familiar with your particular situation.
OTOH I slamed a poster on another board who flaunted education. I told her the most dangerous person in the world is an educated idjit. In my day in the army we called them "Smart College F**ks".