Best way to fight anxiety is pretending to not give a shit and go out there and openly stutter. Trust me, I have seen this work for \~15 **severe** stutterers and it worked for every single one including myself. Pretending turns into thinking "well I did it, so it wasn't that bad", which turns into actually caring a lot less. This leads to less stress, which results in less stuttering. The first step is the hardest and motivating yourself to do it alone would be even harder, but you can do it nonetheless.