I can really relate to your situation because I used to have extreme fear of public speaking and stage fright cause by having to give a class presentation at school at the same age you were, 9 years old - my knees shook, I sweated like crazy and my voice was quavering. In the week prior to that report I was nervous as can be, dreading the report, and really a mess.
The good news is there's definitely hope for you and I suggest that you take your time in building up your confidence. Start simply and easily by emulating speakers that you estimate have no stage fright or fear of public speaking. Emulating is easy, just "act like them" but don't over do it, you're not imitating, just emulating qualities they have like how they stand, how they gesture, how they move, how fast or slow they talk.
Practice being able to defocus your eyes while speaking as this naturally triggers the autonomic portion of your nervous system which is responsible for creating relaxing feelings in your body. There is a short video of how to do this at SeminarAcademy.com. Also, practice labeling your body sensations as excitement instead of nervousness - often the only difference between nervousness and excitement is what we tell ourselves our body sensations mean to us.
It's true that your bad experience was due to putting too much emphasis on yourself and what people might think or feel about you and that puts too much pressure and worry on you. Do you have a strong religious or spiritual faith?--if so (and even if not), get yourself to feel connected and concerned for the well being of your audience because that takes the focus off of you; think of them as your friends, your brothers and sisters, as it were.
If I - a nervous, shy, introverted kid - can overcome stage fright and fear of public speaking, so can you.
One more thing: I strongly suggest you alter your relationship with your memory of that event because that can strongly and negatively influence you in the present and the future. Try revisiting that memory as if you are an objective observer - as if it's you visiting from the future - and try to have empathy and caring for that younger you; what would have made things turn out differently? What qualities and characteristics would you have had to possess then in order for that even to have had a positive outcome? Replay the event over and over in your mind but change the outcome to a more desirable outcome - no, you're not fooling yourself about what happened, you're just changing your relationship in the present to what happened in your past. Resist the temptation to relive the experience as if it was happening all over again, instead, see it from the outside with curiosity about what would have changed the situation to a more positive outcome. Imagine being able to speak in the future with that more positive outcome.
Those are just a few things to get you going, feel free to look at the articles on conquering stage fright and fear of public speaking at BestPublicSpeakingTraining.com and you'll find tons of great ways to deal with fear of public speaking - my personal favorite is "the hero process".
Finally, accept that this happened and don't resist the facts. Change your relationship with that event, but also give yourself permission to have been a 9-year-old child who was overwhelmed - the only thing that means is that you're a normal human being with feelings.
Let me know if I can be of further help, and I hope at least some of this helps!