I have also found that sleep has to be my #1 priority. It's hard in the moment, but I did as you describe--set a list of deadlines & activities to create a schedule. I also started marking on a calendar every time I did the bedtime routine (turning screens off, taking my meds, etc.). Seeing stars on the calendar helped me track when I was taking care of my sleep needs (so if I missed a night, I could see all was not lost). It also made me feel good to see my progress.

It's not easy. Hang in there.