It's a difficult situation for both of you with family issues and Covid even making it worse. I know from my own experience with relatives, that people somtimes give up when they feel that life isn't worth living for them any more. I try to tell myself that they may be better off after leaving us and not to look at it as a personal loss.
About sleep, I didn't use any drugs except very light natural ones on sparse occasions. There was a period of several weeks in 2013 when I would wake up every hour at night with my stomach hurting a little, get up and do some little exercises and fall into sleep again for another hour. But usually I sleep quite well now.
Changing diet in small steps can encourage you to have control over things. But I think it is also advisable to seek recreation and get your mind free (tried yoga?).
Steve