Strength or Weakness??

There is one thing about me that I know is different than some people. While I am a pretty shy person, I am also very blunt. I am not afraid to say what is on my mind. I think honesty is a great trait to have and have always been proud to say i'm an honest person. I'm starting to wonder though if sometimes being blunt and honest isn't always a good thing. There have been relationships in my life that have ended due to my blunt honesty. There are certain things people don't like to hear and by tellling them these things, they felt the need not to be friends anymore. I know that most of these people were probably not true friends if they couldn't handle me telling them the truth, but it is still hard losing friends. I'm now just trying to figure out where the line is with when and how honest to be with friends. Do I not say something and keep their friendship, or say something and risk losing everything? I just really don't know anymore.