You’re situation sounds a lot like mine. I never even had a stutter as a kid, it sort of just developed out of the blue for me when I turned 18. I’m 22 today and still have it. Like you, I am also still trying to figure out how to get my fluency back. A couple things I’m doing are cutting out porn/masturbation as well as reading out loud for about 15 minutes a day to a metronome. Best of luck man