harassed on ig direct???

So a few days ago I was tagged in  a picture from someone I DONT KNOW from another country and added to a group chat. Then one of the users started saying horrible things about me in said group chat, so I blocked and reported him. I can still see what theyre saying in the group chat and I checked to see if there was anything else and someone must've taken a screenshot of something I posted and uploaded it in the group chat, proceeding to make horrible commentary. I don't know what to do, or how to get this to stop.