You can totally get through this. Here's how:
Acknowledge your feelings
You're not going to get anywhere if you avoid your feelings. Admit it, even if it's just to yourself, that you have feelings for your crush.
Ride the emotional roller coaster
You might feel anger, sadness, regret, or something entirely different. Whatever it is, it is important that you completely feel all of the feelings. Put in some headphones, and go for a walk. Don't be afraid to think about them. And cry—cry a lot. Cry until you don't feel the need to cry anymore. Scream, punch your pillow, and turn the music up even louder.
Write them a letter...and then burn it
Get your Eliza Hamilton on, and strike a match—it can be very therapeutic. Put everything that you would say to them on paper. Everything from the beginning of your feelings for them to where you stand now. Be completely vulnerable. Materialize the thoughts that are inside your head. It will feel good to get them all on paper and even better to watch them burn.
Distance, distance, distance
You don't have to disappear, but try to avoid situations where you'll be seeing them. It isn't easy to be around someone you have feelings for, especially if it's unrequited love. The distance will help you focus on other things in your life instead of obsessing over body language and hidden messages. The longer you're away from them, the more you'll realize that you can survive (and even thrive) without them.
Talk to your friends
Friends can be there for you in tough times, and they can give useful advice. It's always a good idea to have an outside perspective, so find a friend that you trust, and explain the situation. They can be a shoulder to cry on and can help steer you in the right direction: toward feeling better.
Eat some ice cream
At this point, you've earned it. Ice cream is a sure way to brighten even the worst of days, and it's definitely the best part of any self-care routine. Stay strong, and you'll be back on your feet before the carton is empty.