Someone Asked Why Did Loki Freak Out in TEODD Ch 6?

He had a flashback. The man has severe PTSD because of all that happened while in the Chitauri dungeons and after that in the Asgardian dungeons. He also has been hallucinating off and on over the course of more than a year and while his mind is slowly healing in that regard, it’s causing him severe anxiety as well. And then Thea had to go and f*** with his mind to make him stop trying to kill Steve, which stopped him, but f***ed with his mind even more.