Yeah, you're only 18. She's still acting like a high-schooler. It's hard right now, things like this is never easy, but you'll feel better as time goes by and be much relived that you let her go when the more mature woman blesses your life. And you NEVER NEED a drink to get through anything! Alcohol may be fun at parties at times, but it isn't a solution to ANYTHING. So please, don't have a drink cause you're stressed.