First of all, don't be surprised by girls seeming lesbian appearance, I believe it is normal for females to not care if others are naked, or whether they are touching. Example, my slutty straight friend went into a shower with 2 of her naked friends, acted totally normal.
But kissing is a different matter. But don't freaking be depressed, you are 15, you are in high school, I'm sure there are PLENTY of other girls for you to take out your hormonal lust on.