If you had turned on the history log, you would have had a detailed record of what you had done to the image and therefore could have worked backward or started over again. Unfortunately I do not believe there was any way that you could have gone back to the delete state. History takes up huge amounts of memory and / or scratch disk. It also slows down
PS performance as the number of steps grows. So
PS is quite eager to purge any states that it can.
Regards, Murray