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? 
Please don't destroy yourself with self-harm, drugs and abusive relationships. Please realize that you're special und you're worthy. You deserve to feel good, everybody does. Please don't think that you'd never make it, because you did. You overcame your biggest fears. You're going to find your soulmate soon, someone who understands and sees your pain, someone who loves you regardlessly. Keep your head high, it will get better, I promise!
Stop worrying, sweety!
You may not be able to talk to your younger self, but you can write a note (or many) to your future self. Check it out:https://www.futureme.org/
Cool! :)
1) Never Give Up.
2) Believe in Yourself.
3) You are Beautiful.