I don't have a method of stopping this: but I do have some advice. Firstly, story time - so when I was a kid, I didn't speak and during my teens I had a pretty intense stutter with blocking that went away by the time I started university properly aged 21. Cool, good right? Well, during the end of my 1st year/start of 2nd my speech went to hell. I had a stutter again, and dysarthia, and a lisp - on a \*performance\* degree where I had to speak, on stage, every single day and things just kept getting worse. My mobility declines, I began experiencing spasms and pain and my balance was shot. I went from an able bodied, fluent person to a full time crutch user with a noted speech impairment within about 6 months. Obviously, this was horrendous. I stopped going to university for a while, before one day deciding fuck it and going on in. What I found, as soon as I had decided that fuck it, what I had to say was valid and other people's reactions didn't matte- well, it didn't stop them reacting, but I was in a position where i could teach myself not to care. They had to listen, because - I told myself - what I had to say was important, not the way I said it. It took a while to internalise this, and it only worked through continual practise and continually putting myself in situatons in which I was dysfluent and just, riding it out until I could speak again. It sucked, but it got easier everytime and now - I actually don't care. I can fuck up on a word, stutter, block, hell even be completely un-understandable and it just is. Other people can react however they want, but I honestly couldn't care less - beyond sometimes getting frustrated when they don't engage properly. So my advice to you would be to stop thinking of it as a problem, and just let it happen. It becomes second nature, and it'll do you in good stead for the rest of your career and socialising.