I too spent a long time feeling ashamed of my sexual desires and kinks. One of the best comparisons was with my best friend at university. He came out as gay in his second year and spoke of the relief at not having to hide his sexuality, no longer being forced to feel ashamed or dirty by who he is.
I think a similar comparison can be made to those of us interested in BDSM- most of us are still in the closet, both publically (though wouldnt it be a liberating world if kink was as socially accepted as homosexuality is nowadays in the West) and privately with our partners (for fear of rejection in bed).
Because I felt ashamed at who I was, and because I couldnt reconcile my thoughts and definitions of what a good person is (Someone who does not hurt others) with my sadistic desire to combine pain and pleasure, I felt I couldnt love myself. That made for a very lonely 10 years, because if I couldnt love myself for who I was, how could I ask another to love me.
I finally met a girl who I trusted enough to open up to and explain my desires to. And it is a liberating and joyous feeling to have someone know the true you. Like you, it isnt something I'd tell my family about, but coming out of the closet to one person? If its the right person?
Perhaps thats enough. It is for me.
V.