You are most likely describing benzodiazepines. (Aka benzos). They work on the “calming” brain cells and decrease brain activity (similar mechanism to alcohol). They are very effective at getting rid of stuttering. Unfortunately they are highly addictive and it is NOT a good idea to take them everyday. I personally find that Clonazepam cured my stutter 100%. It is really useful for job interviews or first dates. Ask your doctor and see what they say. Sounds like you would benefit tremendously. Remember definitely not everyday though!