how do i deal with anger??

i don't know what to do anymore. i have extreme anger issues, and nothing helps. i've had therapy, tried grounding, tried walking away, nothing works. people say "just don't get so worked up about it," but they clearly don't know what it's like. i've broken multiple expensive items like my phone out of anger. i've physically hurt myself out of anger because that's the pnly thing that calms me down. i genuinely want to kill myself out of just anger. i'll start scratching my arm until i'm bleeding, punch my arm until it hurts really bad and bruises, or bite my arm hard enough so that it's sore and bruised. i want to control this before i hurt someone or myself really badly, but nothing helps. i need advice, please.