I know it can be hard to break that pattern of sleep. When that happens to me sometimes you can be so tired you must take a nap in the afternoon. Again the night comes and back awake again. ;) It takes a while to get back to normal routine.
I had a good scedule going for awhile but if I get started on a “project”..I stay up and before I know it.. it is morning..I am a born nightowl.