Before my current recovery I was on practically every known antipsychotic and although there were ones that made me sleep late into the day I never slept
for a whole day, let alone 4 or
5 days. I would strongly suggest seeing
a neurologist and getting a sleep test done. Also if your psychiatrist does not take this seriously I might think of changing to another one. Excessive sleeping can be caused by episodes of depression but regardless when its that long a time it should be taken seriously.