I’m not gonna comment on the first part of your post, you had enough responses about that already. Propanolol is a beta-blocker , meaning it suppress the fight-or-flight response that the body generate when exposed to a stressful situation. It is particularly efficient when doing presentations or job interviews, as it can makes you more calm. For everyday situations, not that much. Unless you’re the type of person that stresses out or panic on everyday interactions. SSRI are used to treat depression. If your stutter is being aggravated by your depression, then it may help you. It won’t cure, but it helps seeing life in a more positive way.