<human>: Give me the gist of the text in a nutshell

Hey /r/needadvice, I am stuck deciding my future. I'm a 24 y/o male, stuck at a dead-end helpdesk job who wants more. I just got married (no problems there), but don't want to be stuck in IT forever. A few years ago I decided I wanted to enlist in armed forces, but decided against it because of my wife (fiance at the time). I made the sacrifice for her, but haven't been able to get that out of my mind for around 3 years.

I recently found that I have an opportunity to return to school for engineering (6+ years though). Wereas Mechanical/Aerospace Engineering intrigues me (also the pay is great), although I don't think I would enjoy being behind a desk 100% of the time.
My wife says she supports me with whatever decision I make, but I know she hates the idea of me enlisting and being gone for an extensive period of time and being potentially in harms way. I have been racking my brain with what to do for years, becoming depressed due to stress and work and it's taking a toll on our relationship - so I need to decide soon.

What can I do? Are there other options for one who wants to work with his hands, help people, and make an impact on the world?
<bot>: Can't decide careers, one hand-engineering, other hand-military. Wife doesn't want me in the military, but wants me to be happy.