Are you going to be the bitch of your fear or is your fear going to be your bitch? You won't be able to talk if you don't dissolve your shitty habits first. You speak fluently and are a capable person, but only when you are alone? Bullshit, you can do it. You must do the work first, it is a personal job. The limits are in your mind. Read books about stuttering and more, stuttering is not just a physical act.