my mother and brother slandered me from another continent saying I'm argumentative and threatened Many people where I live but they have no knowledge of this whatsoever my mom said I mustn't argue with people. now I suffer from waswas if I ever argue with anyone does that mean I'm sinful?

From the multiple waswas questions that I have received from you, I highly advise you that you seek a trustworthy Muslim doctor whose field is helping others to deal with these obsessive thoughts and behaviors. Don't hesitate. May Allah subhanahu wa ta'ala protect us and you. Go to those specialists to help you, and if one of them did not help you or was not proficient enough, then look for another one and do your best. BarakAllahu feekum.