Do you mean that you hate the condition of ASMR or that you hate the sounds that usually trigger people's ASMR and the videos people make to trigger it? As for me, I have something very similar that is triggered by sounds, some good and some really bad, but whispering and the like does absolutely nothing for me. If I watch an ASMR video it's just mildly annoying unless there is something else that triggers me, like they have an accent or they use words that are triggering.
That's a real jerky thing for your brother to do. Is he a kid? I hope so, as it is a bit more understandable for a kid to try to pick on his sister than it would be for an adult. Still, it's a very jerky thing to do. I'm sure he's just trying to tease you, but he doesn't understand that it isn't just mildly annoying to you, it's very upsetting. Maybe you should try to explain to your brother how it feels in a way that he could understand. Maybe tell him something like, "When you play those ASMR videos for me, it feels like it would feel to you if someone kicked you in the groin." Sorry to be graphic, and I know that's probably not exactly what it feels like to you, but that would get the point across that it is seriously unpleasant, not just mildly annoying.