Read the text and find out main phrases and main sentences.
Main phrases:
figure out 、cool down
Main sentences:
.We used to study and play together,but ever since last Friday,she hasn't spoken to me.
I considered all the things that could be wrong,but I still can't figure out what the problem is.
Sometimes it's pretty hard to tell what's wrong in a friendship.

Try writing to your friend or you can ask another friend for help.
If neither of these things works,just leave your friend alone.
She may need some time to cool down and think about the situation herself.
If yes,go directly to her and say sorry.
If your friend wants to end the friendship,there's nothing you can do about it.
But even if you're not friends anymore,you should still be friendly.
Say hi to her when you pass her at school.