betrayed by frenz

I felt moody today. A super upset day..
I asked my friend what actually she wanted to tell in phone but she dint tell. Then she said she will tell me in the school. I thought she wanted to tell a joke or something else.
I was still okay in the 1st and 2nd period. After that i went for recess with my friend..
But after she told about the incident, i felt like betrayed.
I was super shocked for what my friend told me..
Then the recess ended.. I was thinking of that incident in the way back to class.
I felt unhappy in the class, can't concentrate in the class at all..
When I was thinking of it, i cried..
I felt I was really betrayed by a friend that I thought I can believe him.
What i told him something bad about a person, he went to tell that person. I told him don't tell anything especially that person, and then he promised me but now he don't keep his word.
I was really very dissapointed on him..
Now i really really don't know whether can believe this friend or not..
I felt that this school which I'm studying is really full of gossips..
I really have the feelings which is wanna leave this school as soon as possible.
I hate those people's mouth who like to gossip and spread some incorrect news..
Now I really very confuse and down, don't know how to face those people that misunderstood me..