inexplicable dilemma

Books are, and have almost always been, my best friends (second only to good music).  An escape, a companion, a distraction, encouragement. . .

But, if this is a true relationship, it cannot be without faults. . .

The days of escape and distraction are glorious gifts, but in the same manner, some books will hurt you.  While I read, I release my grip on self, and become completely vulnerable to the instability of the characters, taking it on myself in an almost supernatural way.  The pain, injustice, and heartbreak of this fictional person becomes my own.

Maybe some would consider this a testament to the authors talent, and I suppose it is.  But in my human weakness, overwhelmed with these feelings, encountered only by proxy, that I am not equipped to deal with. . . it is too much.  I find myself broken and lost, drowning in a situation that is not actually mine.

How do I create and maintain boundaries between myself and these characters, without losing my treasured relationship with books all together?

And how, for the love, do I explain my vicarious pain and crippling heartache to those who have never connected in such a way?