So this is something that I'm just now finally getting a handle on, but it's been instrumental in overcoming my issues: I've stopped caring if other people hear me stutter. I understand that won't happen overnight, but slowly I think you should work to this end. Once you stop worrying so much about everyone else, you can realize that you have something worth saying, and god dammit you're gonna say it. If you screw up, then your state of mind needs to be one of 1)acknowledge to yourself that you weren't perfect, and 2) understand that's OK and move on to the next task. In my mind, when you don't talk out of fear of stuttering, then you're letting it control you. Don't let that happen. You're the one in control of what you say, remember that.