A matter of trust

I identify myself as a trusting person. And maybe that's why it's so hard for me to feel driven out of trust by someone.
It's hard for me not to share the day to day important stuff, when it's usually such a natural process. I feel as if I were lying. Is withholding information the same as lying? I have often wondered this, and have still not come to a satisfying answer.

For the time being, I'm going to hold my horses. I think it's no accident my gut tells me not to trust, even if my spirit rebels against that feeling.

Billy Joel and his music accompany me in these doubts... he sings that "it's always been a matter of trust", and also sings that "honesty is such a lonely word, and mostly what I need"... In this case, I feel I need honesty from the other person towards me, and I need honesty in my life, because i don't like living without it.