Story of Recovery: Matt

I am in my mid 30's and a dad. I grew up in a very fundamentalist church, of which my dad is a minister. He was never as strict as some of the other preachers, so I thought I escaped relatively unscathed, but now I know I have a few scars. Now, instead of the "conviction of the Lord" I have fear and guilt of disappointing my loving parents...or should I say, lack of beliefs. How do I tell them that I've changed without making them feel horrible? Do I tell them at all?