try to focus on the present. if you are healthy, try to put the worries out of your mind. most folks who go into nursing homes have gradually gone downhill and have time to prepare for someone to care for their animals. i don't know where you got your cats, but the shelter i got mine from wants him back if i can't care for him.
as for missing them, that will be hard. when considering nursing homes, you can ask if they have therapy dog visits scheduled.