Okay, if you go to the forum page for q & a, for instance, on the right hand side just above the box full of topic threads, you should see a list of things you can do. One is "Your drafts and posts." Click that, and you'll se a list of your posts, as well as a ? that says "Saved drafts?". Click that, and then you can get to the message again and post it.
I hope that makes sense; I did it twice myself and tried to remember the directions for you