I can’t tell for sure what it was, but jhana might be a possibility. Maybe first jhana? The fireworks thing sound like first jhana to me, although I’m no expert.

I have never ever been stuck in jhanas. If you are under the illusion that you can’t get out of it, for some reason, just do a subtle movement with a finger. I have woken up in jhanas, or at least with jhanic qualities to my mind state (exactly what qualifies as jhana is much debated, so I can’t say anything certain) but that has never been a problem as far as I can see. Pleasurable, sure, but they always end. I think fear might end them effectively if that were to be the case. Then again, if fear arises, the jhana has probably already ended. These states are very temporary.