Someone I talked to recently asked me to blog about liking someone who is unavailable. I know that I've personally struggled with this many times, so I decided to do it. As humans we have many different emotions. This is a difficult thing to deal with because it adds to those emotions. So here is some advice:
One thing that is hard to do is think about the situation, whether or not the person you're crushing on is really a possibility at all. Now I'm not saying that you should be thinking "oh they're too good for me...", NO. You're valuable! More so than you know! What I mean by this is think about both your circumstances and theirs. You're single, maybe lonely, and wanting to feel the affection of another person. They're in a relationship. Is it right for you to intrude on their relationship because of your feelings? Probably not. But here's the thing you should understand, it's not wrong or foolish to have feelings for that person. Sometimes we can't control our feelings. It's how you act on those feelings that can put you in the wrong. So don't beat yourself up for feeling a certain way about someone.
How do you make these feelings go away? Well, that's a hard thing to do. If I could figure out some concoction that would help with that, trust me, I wouldn't have to worry about spending money to get gas tomorrow. :P But one thing that could be helpful is talking to someone you can trust. A good friend or accountability partner. Someone you know will tell you how it is no matter how much it may suck to hear. (Those are the types of friends you should find if you don't have any.) Maybe they can put things into perspective for you. Maybe they have a way of seeing the situation that you've never thought of. Sometimes it helps, sometimes it doesn't, but it doesn't hurt to try.
Something to think about: how much time are you spending with that person? Or how often do you talk to them? Does that add to your feelings? Does that give you false hope?
If this person doesn't know how you feel, maybe they think of you as a good friend, in which case, maybe they tell you a lot. I don't know about y'all, but I rely on my friends listen and help me out when I need their support. If this is the case, it may lead you to believe something that may not necessarily be true. When you're in a situation such as this, it's easy to read into things. So just be aware of that.
Maybe for you, the best thing would be to take a break from them. Now this can be hard. Maybe you and this person are close. Maybe it would just be weird if you all of the sudden "dropped off the face of the earth". My suggestion is to casually keep your distance. Don't go out of your way to contact them, but instead make yourself available for when they need your support.
The last piece of advice I have is to pray. "pray continually," 1 Thessalonians 5:17 Pray and be patient.
I hope this was helpful! Have a wonderful day! :)