You're not alone, mine also got worse out of nowhere when I got to 26. There used to be times I would speak without stuttering for a day or close to but now it's impossible. What helps me now is speaking regardless of the anxiety of not knowing when it'll happen and stopping my mind from obsessing over the words. I also yell out the words and if anything is about to start I pause then wait for a calm feeling in my head, take a deep breath then continue.