Speech therapy is fine, and if it works for you thn that's great. However, if it doesn't - go and test your embarassment. It sounds dumb, but I have a stutter and dysarthia (slurring of words) - at times my speech is totally indiscernible and to combat my deep insecurity about it as a teen I went and got involved in theatre, eventually leading to my undergrad degree. Talking on stage, at times without a script or even the faintest idea of what I was doing not only gave me vocal training, it also made me realise that speech dysfluency is fine. I actually \*like\* my vocal differences now, because they make me more interesting to listen to. Hell, on days they are a bit better I honestly feel a little disappointed because I'm secure in my dysfluency- my voice has become internalised as who I am and I only notice it when there's a change. If it wasn't for theatre, I'd no doubt still fulfil the criteria of selectively mute. Testing my embarassment and anxiety allowed me to kinda bait it and that weirdly adversorial stance made me stronger than it. I remember 1 day my speech was really bad, and I didn't want to leave the house nvm talk - and I ended up thinking 'well, what's it gonna do? What's thw worst it can do? Panic attack? Have to go home? Fine. Bet.' Setting it up in this weird challenge format helped me out, but having a supportive space to do it in helped me arrive at that ability. I'd say go get involved in the thing you really don't want to do, whether its theatre or public speaking or whatever. Learn to use your voice to communicate, focus less on the actual talking and more on what you want to say and the emotion you want in the words. At least that's my 2 cents.