I am so sorry your student is going through this.
Yes, time to stop sharing information with the roommate. Tell little to nothing about academic, club, and social life. It sounds like a certain amount of ignoring this roommate is in order too. Maybe as little amount of time together and not much in the way of responses will get the roommate to focus elsewhere?
This sounds like a “get through” situation. In the meantime focus on other relationships and have your student keep an eye out for someone else to room with. Things usually open up second semester. Maybe your student can find someone else to move in with? I don’t see this one improving.