I've seen “over-preoccupation” in a paragraph and searched for the meaning, but I only came across results with "preoccupation" - without the "over".
Let me quote the Cambridge Dictionary
We can use over as a prefix to mean ‘too much’. We connect over to the word which comes after it, sometimes with a hyphen after over:
That new restaurant is overpriced if you ask me. (the meals are too expensive)
I didn’t enjoy the play. It was a student production, and everyone seemed to be overacting.
over-preoccupation = too much preoccupation