Join the army or stick with girlfriend?

I'm 22 years old. I've been together with a wonderful girl the past 3 years. We got together right before I had to do my service year in the army, and it worked out. I finished the year, went home and worked in a store for a year. Now we are studying in a bigger city, and we've moved in together a small apartment. Here's the thing: I really miss the army. I feel like I really belonged there. I've never been great at something, except being a soldier. It's my dream job. I'm really considering to enlist; considering starting a life as a professional soldier. But I haven't told her. I don't know how. I'm 99% sure that she will leave me if I tell her. Sometimes I lie awake at night, thinking about it. Missing the military life, longing for it. Sometimes she catch me doing it, thinking, and asks me if there's something wrong - asks me "what are you thinking of?" I usually answer "nothing, just trying to sleep". So my problem is, what should I do? Should I tell her, and risk that I break her heart? Or should I just .. find something else to do, keep the girl, but always long for my dream job?

First and foremost Hogfed, you're no good to your partner if you aren't being true to yourself. While you deny yourself, you're partner will only ever see some of you, not the true you. If she accepts the true you, then it's true love. She'll wait for you because if she truly loves you, she'll walk over broken glass for you. She'll never stand in your way for you to fulfill your quest of rejoining the military. If your relationship was meant to be, then she will support you totally in everything you do because she'll have the NEED to support you. Be true to yourself Hogfed and follow your instinct. Don't waste the person you really are.