andrew, you need to chill. they died because you put a bunch in there and now you're gonna get "a ton more" and they're gonna die as well. Bream/Sunfish can get nearly oscar sized and produce a lot of waste. as of now whether your 500 happens or not you only have a 55g tank and its already stocked well. there is no reason for you to keep these fish knowing they are going to die.
haha yes i agree you cant shove that many sunfish into a 55g they get huge and when they are bigger the crap is like dog crap i have a 150g and its not big enough for my natives i would take it slow dont catch all the fish shove them into a tiny tank and then hope they survive i personally wouldnt recommend keeping even 2 sunfish in a 55g but thats just me im in the works of getting a 250 and then eventually a plywood build for my natives