I found out helpful tips to get these trophies. For By My Hand Alone when you get bend time use it before the tall boys so it can be easier get to the enemies, be sure to kill the one with music box with grenades, don't use remedies until you get bend time, kill the tall boys first but on round 12 kill the one on the opposite side from where you start. Time management can be easier to obtain on bend time massacre and youtube videos can show you how to get it. I know by my hand alone is based on luck but I hope these tips can be helpful on getting those frustrating trophies.