Not even that. A week at most (and if we take Hook literally that Emma hasn’t slept since they came to the Underworld, then it’s less than a week given human constraints)
I dunno if I’d take Hook’s words literally, because “hasn’t slept” may just mean that Emma has gotten little sleep, rather than not sleeping at all. One thing with this show is that they’re pretty ambiguous as to how much time passes in between episodes. I mean the entire Camelot quest took place over 6 weeks based on what they told us at the end of “The Dark Swan”, but it may not come across as that long when watching all of the Camelot flashbacks back to back.