[gc22browsing]

Ok, so X is your brother's sister-in-law. So she is sorta family now.

From your telling of the situation, X appears to have had strong feelings for you. You obviously did many things for her and she benefited from that.

You could move to another city and break all contact. X has support around her and would most likely recover from the heartache with time.

OR you could seek out relationship counselling to resolve the situation. Your explaining "in excruciating detail" suggests to me that you have not entertained any alternatives to your view of what happened.

You being concerned about X being suicidal or falling into depression, shows that you do care for her. I would recommend the professional counselling path to resolve this matter and possibly empower you and X to better deal with life's curveballs in the future.