It's hard to see what scope there is for the problem to get all that much better if you are required to be awake from 1am to 3am (or later) every day. It seems like the best you can do is to try to establish a routine of always going straight to bed (and not reading, browsing the internet, etc., once there) after dealing with your mother, which might maybe get you a ~ 4am-12pm sleeping time on typical days.