I've got a problem. My sleep schedule is FUCKED UP.

Yesterday, I went to bed at around 8:00 AM and got up at 10:00 PM. I don't normally sleep 14 hours, but I've somehow become nocturnal; sleeping from 7 AM until up at 5 PM isn't particularly unusual for me. I'm not actually sleep deprived, but always sleeping through "normal business hours" tends to cause me problems - I can't get to the bank even when it's important - and isn't very convenient for my girlfriend either. My father jokes that I must be turning into a vampire because I'm never awake when the sun is up. Now, I don't actually have a job or go to school, and my only fixed-time obligation is to help my wheelchair-bound mother get into bed, which tends to start at around 1 AM and finish between 3 AM and 4 AM. (There's nobody else to do it at that hour and getting her to go to bed at a different time, or to get ready faster, is practically impossible and not worth the screaming.)

Any advice?