Every table in SQLite comes with a “rowid”. You just need to set that rowid into an actual column.
ALTER TABLE ep_2017 ADD ep_id UPDATE ep_2017 SET ep_id = rowid
When things are really getting desperate, start searching for snippets of code on GitHub. Someone, somewhere, did the thing you’ve been trying to figure out for hours.
You just need to be smart enough to figure out what it is you need to know.
$0 in the console