Cichlid disappointment

I've been keeping a Convict in a 10 gallon aquarium for about 4 years
now without incident. The aquarium has nothing but gravel in the bottom
with a back of the aquarium filter. My fish seems a bit nervous/ scared
at times and I recently read that Cichlids prefer to have something in
the tank like a plant or other place for cover, so I added a small
ceramic cave. I have hardly seen the fish since as he/she spends 95% of
the time in the cave. Other than that, he/she does still seem to eat
ok, although because of the reluctance to leave the cave, he/she misses
some of the flakes at feeding time. In retrospect, I'm wondering if it
was a mistake adding this cave. Any thoughts would be appreciated.

Thanks,
John