In terms of porn, I don’t think it will have a sufficient impact on stuttering apart from getting nervous around the gender that you’ve sexualized. In terms of masturbation, I don’t think that, by itself, it has negative effects on stuttering however I do think that it reduces productivity which could loser self esteem. This is why I don’t don’t shake hands with the milkman in the morning. A challenge like no fap could have a positive effect on you. Not because splooging brogurt direct affects stuttering but because the challenge is something to work towards and will build self esteem