For the girl who wasn't loved back,
Let's just say it. Love sucks.
It can be a beautiful thing, except for when your feelings aren't reciprocated. At that point, all you want to do is lie in bed for weeks. If this is you, or was you, you're not alone. I've been there. And it sucks.
But let me give you some advice: don't focus on some dumb guy who was stupid enough to hurt you. Embrace the wonderful people around you, and focus on all the good things in life.
You might feel like he was your everything.
You might hope that he realizes he made a mistake and come back in a couple of days or a couple of weeks. I don't mean to be blunt, but don't get your hopes up; you'll just end up disappointed. He was stupid. If he couldn't realize what he lost, that's on him, not you. You're going to feel worthless. You're gonna wonder for months why he didn't have the same feelings for you as you did for him. It's not your fault.
Don't wallow in your sadness.
Distract yourself. Spend time with friends. Color in coloring books, draw, write poems, keep a journal, spend time with family. It's okay to be sad, just don't let the sadness consume you. It will destroy you. You'll watch your friends get into relationships and no matter how happy you are for them you'll still wonder why you're not good enough for anyone. But you're more than good enough. You just haven't found that person yet, and that's okay. Everyone's life is on a different schedule; a different clock. Be patient.
There is someone out there for you.
Everyone has a soulmate. But you can't search for your soulmate; you have to let him come naturally to you. Have patience. Don't search for your prince charming, because you'll just end up hurt. And please, don't run back to him. You'll want to, and you're gonna think he's not gonna hurt you again, but he will. He did it once, he's more than capable of doing it again. Don't fall for his trap.
In the meantime, focus on yourself and make yourself happy. Embrace the goodness around you. Write down one good thing that happened each week. Don't focus on the negatives. And remember, you are more than good enough.