You're not alone at all!! This is me 100%
It took me the longest time to finally post on this site and before that, I would seriously think up a whole reply to a post but never even attempt to type it out. Even now, I stare at my replies for several minutes before finally posting it. But I'm slowly starting to overcome that as I get more involved in this site because it's such a caring and accepting community. Trust me, don't hold in what you want to say. Letting your voice be heard is seriously such a relieving feeling.