Help with what to do?

I need some help! I went from really eating nothing to eating so much all the time! I weight 130 pounds. THis is not me, not who I am! My goal is to weight 115 pounds. However, I am unsure how many calories to eat to get there. I excercise around twice a week, I would rather round down that up. I am 17 and 5' 2''. Please help me! I dont count calories now, I used to. I am unsure how many calories to eat to lose this weight! I need help from someone, please guide me in the direction of where to go!

Need to lose 15 pounds!!!