How to be happy as sensitive person...

You cant control peoples behavior. The only thing you can do is ask yourself why it affects you the way it does, and if your feelings are worth your friendship or if you think you can learn to accept it. If your friends hurt you, you must be able to express your feelings toward them. They may choose to correct themselves or not. If they dont, either you should accept their behavior and learn to embrace it, or find new friends who will care about your feelings and ideals. Friendship is not a one-way thing. Both parties are equally important in any relationship! :)