If you could write a note to your younger self, what would you say in only three words?
I had two thoughts. 1) Words can hurt. 2) Try your best.
What would your note say? 
Communication is key. Look at people for the person they are, not what you think they are or what others say. Boosting others' confidence will make you happy as well, not tearing them down.
Elouise is poisonous!
(A 'friend' I had when I was younger)
THIS WILL PASS
Simple, direct, except my younger self (or even my more recent self) likely would not believe me.
Mine would say, stay quiet, don't follow the crowd
Don't get too comfortable, just when you do life will show up and change everything.
You are beautiful
You can do it
you are loved. Or, it's okay.
I would say ...love yourself cause you are unique ....do things for you and not for the others!
You are beautiful