It is impossible to get stuck in hypnosis — it is simply a natural state of relaxed, focused attention.
In Guided Hypnosis, there is an additional layer of reassurance: I never bring you out of a session until we have received clear confirmation from your subconscious that the work is complete. We always close the session properly, which means you come out feeling settled, clear, and at ease — not halfway through something.
If at any point you felt uncomfortable and wanted to stop, you could simply open your eyes. You are in complete control throughout.