letting go

Does anyone one have advice on not constantly being consumed by stuff/people from the past and their actions? I feel like I've heard every perspective n what not on it like "how people treat you is a reflection of themselves" "you can only meet people where theyre at" "dont take it personally" and none of those things click for me or make me feel better. truthfully idc if its a reflection of them or whatever, they still inflicting/inflicted pain onto me whether it be mental, verbal or physical. nothing has been able to make me truly let go. like i dont get it. why not take it personal if it was done to me? theyre not the one who has to deal w the consequence of their treatment!! I dont go around hurting people cause im hurt so i truly dont know how to get over this stuff.