You're right, reading ch.1 again, his livestream is a Consultation Corner, provided by the TL note. His trauma definitely came from the text he received after his livestream.
I think it's heavier than just a former consultant that had a pretty bad advice then cursing him out on him, if it is that, maybe the advice MC gave had so much a drawback that it wrecked the consultant's relationship or life at home.
Cliche plot says that MC has some involvement with all the current streamers in the dorm. In short, he's most likely a high-ranking streamer. That's just a guess.
So she's like Hinata in terms of skill, Pekora in terms of sadism and enthusiasm but with the face of Korone and Gibara's hairstyle. I can get with that.