I have a weird relationship with caffeine but I’ve learned now that it doesn’t actually help me. I worked in a call center and I would have a coffee as soon as I woke up, a monster on the way to work, a coffee before starting work, and a monster during my break. 5 days a week. For a year. Then I worked as a delivery driver and again, I would religiously have my can of monster. Without it, I wouldn’t feel like I could get through the shift. I cut it out last year because I realized that it was all in my head and that caffeine doesn’t actually do anything for my stutter. I’m not saying this is the same for everyone but have you tried quitting for longer than a few days? You’re stutter might just be worse because of withdrawal symptoms