Its normal for ours 'so-call' friends to stab us in the back and this is the reason I always say, watch what you say to your friend.
I know that it can be painful keeping things stored up inside but think of and outsider to confine me in most cases work out better then with you bosom buddy. But keep strong, release the stress caused by this person and just keep speaking your mind about how you really see this back-stabber.
He/she will read the message and feel embarrass to look at you in the face or communicate with you.
on’t let this get the better of you just keep your head up and be careful net time that you want to confine in another.