When someone disappoints you, look back on your life and think of the people you might have disappointed. Make the disappointment in others turn in to a learning experience - it will turn the hurt you feel into a positive experience.
Be careful who you vent to. A listening ear is also a potential running mouth.… Choose to share personal details only with few trustworthy & close people. That way you avoid sharing to someone who will go about Gossiping about you.