I’m sorry this is getting worse and you’re feeling isolated. I found my stutter has long periods in which it gets worse and others in which it goes almost in remission (although I’d never do public speaking). I never really understood the triggers, to tell you the truth. I’d say connect with other stutterers, maybe work on underlying anxiety (though this also causing anxiety, I know), and try to reframe the issue: you’re going through something, and everyone does in their own way at various points in their life. Do you have activities to engage your body more than your speech? Maybe a sport or similar to put you in contact with others and in which you have to introduce yourself once (you can endure one crappy interaction and then focus on something else)?