Possibly not, but it can't hurt to look around.
What was the source of this 2000-word item? You mentioned notebook — would that be the Notes app? Did you cut it from there, or just copy it?
Is Notes (or whatever app was involved) set to sync to iCloud or some other system? You might check there as well.
It sounds as though your phone may have encountered some kind of memory problem, ultimately causing it to crash-restart. Perhaps one of your attempts to post or paste the 2000 words was actually successful, only your phone was unable to display the result. Worth glancing through everything again, probably.
Sorry I don't have any more inspired thoughts.