I’m not an SLP so take my comment with a grain of salt. I posted a paper about neurogenic stuttering yesterday and that might be worth reading. There are psychogenic stuttering which is what most of us are and then neurogenic, which can be caused by a number of things (stroke, medicine, other) we don’t know too much about neurogenic stuttering but since you weren’t born a stutterer then I’d say it’s acquired stuttering which could include neurogenic stuttering. I would implore you to go see a professional about this.