how do you get over a crush ?

hey everyone!

I have a question, how do you guys get over a crush?

because mine kind of break my heart even tho I known I had no chance with him.

I had a crush on him since the first time I saw him and in that time he had a girlfriend, then he had a crush on a girl AND now he is in a loving relationship with one of my closest friend and yesterday I tried to help him and he said that he doesn't want my help cuz he don't trust me.

Haha my heart is broken but I want to get better and most importantly OVER him so does any of you have any advice ?

thanks ♡