PLEASE ANSWER: How does one show grace under pressure?

[Jody]

To spare all of you from reading a novel, the bottomline is this: Jo is irritated with Alex for being plastic yet Jo still checks Alex's Facebook and Twitter for God knows what. Also, Jo is irritated with Mary because every time Mary's with her boyfriend of almost 9 months, Martin, Mary and Martin kind of have their own world where they ignore the rest of the world and be all lovey-dovey, holding hands, staring in each other's eyes and whatnot. Jo kind of has a habit of lashing out on people through Tweets (without mentioning any names) and Mary started noticing these to the point that she asked me not to tell Jo and Mary asked if I knew something about these Tweets. Jo specifically asked me not to say anything to Mary so I lied and said they were about Alex. I don't know. I feel bad for lying and I want to stay out of this but I just keep getting dragged in. It's giving me a lot of unnecessary stress. I can't wait to graduate from high school yet I fear the kind of drama that will happen this year. I'm losing my mind. I mean, I'm not taking any sides. I guess I'm playing peace maker or mother to these kids since I'm the oldest in our group.