Have you considered adding gizzard shad?

Just kidding. Welcome to the forum.

Assuming your current goal remains growing some big BG [or HBG?], no question your quickest path will be to drain and lime or rotenone...really hard to know what's in there right now, but probably a bunch of hungry predators who are having bunches of offspring that will compete for and with any smaller sunfish.

And don't feel bad. Lots of us have found novel ways to mess up that you didn't even mention.