I’ve heard and read there’s a close link between ADHD and stuttering. Not everyone gets it, but it’s apparently quite common. That’s why some stutterers on ADHD medication find it’s making them more fluent too. My understanding is it’s a dysregulated dopaminergic system in the brain. ADHD presents as too low dopamine and stutterers have overactive dopamine (too high). The anxiety is brought on by your stutter. You anticipate stuttering so you get anxious about it. It’s a vicious cycle. Worth looking into.