you bought a bunch of baby fish with huge adult sizes & not appropriate together. butti's often "snap" & suddenly kill tank mates way before maturity, which is very large. common pleco=huge bio-load & size. Jags are aggressive.
Angels too delicate for the mix, but the 55G tank is fine for them.
Even just googling each fish profile, and specie tank mate info will tell you a lot.
:-/