Well, the request of OP staying in SZ was just a trigger, if it didnt happen there would be always another thing make the 99 displeasure and lauching a war like this.
"冰封三尺 非一日之寒"
I dun think the 99 is really a psychosis. It should be the long term lack of love and care, and the loneliness rooted in her mind, bring her into such a irrational and horrible personality. She is quite pathetic, honestly.
However, it would be either you sufffer or her, there is no solution.