I have some experience with this and I've tried all sorts to "cure a crush". Here is what I've found works best.
A) Get rid of all and any keepsakes from the crush. Don't leave anything behind. That's like a bit of root from which a weed might re-grow - get it all out and put it in the trash.
B) On the same day or night, take the last remaining photograph of crush and burn it; as it burns, say out aloud and in your mind at the same time:
Forgive, forget, set me free, let it be, let it be gone, in the past this does belong. Let it be gone, let it be, set me free, forget, forgive.
C) After that, every time you think of the crush or you get an attack of feelings, stop, hold out both hands, see crush in a bubble (like a crystal ball) in your hands, then raise it up and say, "Forgive, forget, be gone!" and throw the sphere over your head backwards (like water off a duck's back). You can do this as many times as you need for your own higher powers to get the message, loud and clear.
Also, don't allow yourself to dwell or hallucinate or daydream about the crush, or as little as possible.
You should notice a considerable improvement within three days.