thats called anxiety my dude, nowhere near autism (though anxiety can be a symptom of another disorder and it can stems off of that, such as with asperger's or ADHD- which I have). please excuse me for this next remark also, but anxiety like that is a lot.. simpler to understand and treat, whereas autism is a condition that inhibits a persons neurological functioning long-term. autism cant be treated generally (theres medications and cbt for adhd for example but these only help to control symptoms, they don't at all get rid of the disorder/learning difficulty).
what you're describing is a panic or an anxiety attack, which is quite common when put in scary social situations such as presenting in front of a crowd of people. it can be treated with medication if you speak to your GP, and counselling or CBT will mainly be able to help restructure your way of thinking for it- as time and self-teaching is what has helped mine.