Ok ok ... so you guys shouldn't be drinking since you're both underaged anyway, but the age issue aside, as emerging adults, you guys are going to want to experiment with life more and more. You're not around, so she hangs out with her girlfriends and of course she's going to make an effort to have similar interests as them.
If there's any hope of salvaging this relationship, I would apologize for trying to control her life. Just because you can't go out due to work doesn't mean that she should sit at home and wait for you like a dog, you know?
And I know how you feel ... you want your priorities to be inline, but it can't be at your age and contrasting schedules. You guys are going to change big time in the next couple of years.