I’ve had pretty much the same experience as you over the last few years. I’ve seen all the videos of people going on about how mushrooms will fix your stutter, it made mine worse. I got my stutter from a brain injury I wasn’t born with it so I’m sure that affects it in some way. Mdma makes my stutter go away while I’m on the come up but when I’m peaking it gets really really bad, especially if I take a bit to much. LSD didn’t really change my stutter much. Alcohol makes my stutter go away while I’m drunk but yea hangovers are not good. Weed does tend to fix my stutter while I’m high which is nice.