Let's look at these thoughts...

They ignored me! I thought they were my friends!	So, you are saying that these people are not your friends - right? If this is true, why is this a problem?
I guess I am not cool enough to be there friends.	If this is true, why is this a problem?
Because then nobody will want to be my friend and no one will like me.	If this is true, why is this a problem?
Because if Nobody likes me, then I am a loser.	And nobody wants to be a loser, right?
Right