Sometimes I think there are 2 kinds of music. There is ‘private’ music, which is best when listened to while alone, and ’social’ music which is best experienced while in a social setting like a concert or party. If a song gets very personal I find it can be somewhat uncomfortable to listen to in a social situation. The same song though might be extremely powerful when listened to while alone. It might be that the difference between writing a song and performing that song live is similar to the difference between what is art and what is entertainment.
That being said I think there are ways to get personal in a song without making it uncomfortable for a listener in a social setting. You might tell a story using third person or you might use vague language, or humor. The process of writing is often cathartic for the writer but I don’t believe you have to expose all your fears and weaknesses in order for this process to be cathartic. I often go back to a song I have written and see parts of my personality that I don’t particularly like. At that point I usually justify it by saying it was cool to write the song in that manner at that time. Then I move on.
Unfortunately, I find my shadow. It is comprised of the things I dislike about myself. It is always lurking in the background and is largely responsible for motivating me to write. I believe that shaking hands with this shadow is important but I don’t feel obligated to introduce it to others. I like to consider how I wish to present myself while also maintaining the integrity of the emotion. The best songs are honest, but still cool. While I agree it is important for a writer to hold on to whatever is the source of his inspiration, I find it can be very self-destructive to let the beast run too wild without a few beat-downs from his cooler self.
On the other hand there is a law for writing fiction that says the more uncomfortably personal you get the more universal the work. I don’t really have an opinion on that yet.