Disruptive flatmate in private halls

Living with my new flatmate has been horrible since he moved in over winter break. He's really loud from 11 pm to 9 am everyday. He has brought in a bunch of appliances to the kitchen, and there's this constant smell of weed in shared areas. I'm pretty sure his girlfriend is living here too - she's loud, invites friends over daily, and they have screaming matches at 4-7 am. The tricky part is, I'm not close to my three other female flatmates, since first year I've had really distant flatmates that seem to avoid conversation at all costs. I've talked to him twice when I've been in the kitchen late, but he always seems to be in a different world, visibly high. Confronting him is a bit scary, especially since there's no receptionist or security here. I've seen some concerning things, like him dragging his girlfriend's arm through the door (sometimes I look through the door hole when they're being loud) and boxing loudly with his "trainer" friend at 11 pm.I doubt the halls will do much beyond a warning, and I'm worried about the potential confrontation and questioning of who reported him. I don't have anyone in my university city to go to, so for now, I'm just letting it affect my sleep until my wellbeing appointment next week where i can discuss it. I thought I'd ask here if anyone has similar experiences or advice.