Holding this stuff inside creates enormous amount of emotional pressure that builds up and can create all sorts of problems.
I told a friend of mine last fall about what happened to me. We recently got on the subject again, and I told him the story of who I first told, a therapist back in 1997. I actually blacked-out in the session. Not sure for how long, but I blacked-out (may have been even just a fraction of a second, I have no idea).
Anyway, my friend said it was like trying to fit all of Lake Mead through a hole the size of a quarter. A lot of built up pressure. It is good to share this stuff, so the pressure doesn't build up so great, and create problems related to this. This site is a great resource to be able share and get things out. It might make sense at some point to share with your family as well (who you think you should share with), in that it may help them to know you better and create and opportunity for a deeper relationship, and more healing to happen.