I am going to ship off army basic in january for a 11x opt 40. Should I break up with my girlfriend or not?

11x option 40 is a Airbourne Ranger Infantry contract. I do OSUT then Airbourne then RASP and that is about 6-7 months. I really want to stay with her. But the problem is I just graduated from high school( I am 18) and she is going to be a junior next year in high school( she is 16). I know that me going to basic and being gone for about 6 months training would be hard on her. But not all hope is gone because as soon as I am done with my training I will get igned to a ranger regiment. One of the ranger regiments is in washington at fort lewis which is close to were I live now. But there are 2 other ranger regiments in georgia. So there is a 33% I will get igned to fort lewis. So there is always that. But should I break up with her because it would be too hard on her and she needs to have fun in high school or what. But I really don't want to break up with her. So I am wondering what I should do? Am I just being selfish or what? Oh yeah would I get in trouble with the Army for dating a 16 year old when I am 18. I do live in washington.