Might sound basic but have you tried breathing control? I get rages so bad I go partially blind and burst blood vessels in my nose/eyes/ears/fingernails and the best I could advise is to find something to compress with each arm i.e. pillows or stress balls shut your eyes crush something with each hand/arm and keep it crushed while forcing yourself to breath all the way in and all the way out crouching as you breath out and standing up as you breath in.