So many directions. What to do with my life.

I have had a hard time deciding what to do with my life ever since I graduated HS. I worked full time making $17 at a company doing something I enjoyed ( but couldnt stand the company) I joined the military (reserves) and love it with some exceptions. I want to get deployed or move to active duty but im engaged and dont want to ruin my fiances life to drag her around with me all over the country/world. I changed jobs when I came back from military training to a different career but im finding it so hard to do this job now even though getting a better position ( less pay than my other job). It makes it hard and conflicts with my military training I always want to do. I just cant decide what I want to do. Do I just go full military even though the strain it would cause on my relationship, do I switch careers back to what I originally wanted to do which pays more and have more time to go to college. I just dont even know where to start.