Ali...I used to suffer from this phobia BIG TIME! I knew that my chosen future profession would require it, so I knew I had to get over it. Honestly, it's easier to conquer at a younger age (like in high school). I forced myself into taking speech & debate classes so that I could learn more about the art of public speaking. It was terrifying to commit to those classes, but they really helped. The speech class started out with a lesson on conquering the very common fear of speaking in public forums & it really did help me. I guess it's a little late for you to try that route though.
I don't think the typical "picturing people naked" advice ever really helped me at all, but what did help was gaining confidence in the messages I would be delivering in classes or tournaments. I would write up my speeches, practice them repeatedly with a mirror, revise them, practice more & when I was truly happy with my presentation & confident in what I had to say, it really did become easier to convey my thoughts to an audience. It's all a matter of confidence & you have no reason to lack that. You're intelligent, witty & well-spoken, so you should be proud to share your thoughts, views & opinions with others. It IS a very crippling fear, I know, but it IS all mind over matter.
Good luck hon! *hugs*