You're not failing at all, so get that shit out of your head. The fact that you're willing to do something that brings you so much fear & anxiety is a huge sign of strength & is damn impressive in my opinion. There are many people, including people on this very sub, that don't have the balls to do what you're doing. Be proud! The more you work on improving your speech, the more you're giving your stutter a big "fuck you" & taking away any control it may have over what you choose to do with your life. Seriously, take pride in the fact that you're directly facing your fears head on. It's so much easier to run away & complain about how hard your life is.