Public speaking is hard for you right now, because you feel worthless. It sounds like the fact that you failed your first year of college is making you feel that way, when it isn't even really that big of a deal. Just pick up the slack and you will be fine. When you go up there, try not to project the worthlessness you feel, nobody knows what you're thinking. Fake confidence until it get's easier. Once you start accomplishing things, you won't need to fake anything, just be yourself. Learn what it means to love yourself, if you don't already. Don't compare yourself to anyone, don't seek approval from anyone, just first and foremost love yourself. When other people put you down it does not define you, it defines them and their ugly realities. That is their problem and it is probably going to bite them in the ass later on. If you take my advice and really learn what it means to love yourself, you won't feel like you have an inferiority complex. Remember, comparison is the quickest way to depression.