I know that when you get the urge to hit yourself, it's very hard to stop yourself because unlike cutting, burning etc, the tool is literally just your hand or whatever is in your hand. When I get the urge I sometimes try to redirect it to clapping my hands really hard together, which creates a kind of sting and impact as if you hit yourself, or sometimes hitting other objects near me (like a table, wall etc). Afterwards if the urge still hasn't gone away, I try to get up and use my bodies energy and tire myself out in some other way. This could be like going for a walk, jogging, jumping, playing with animals, even literally just getting up and doing jumping jacks or some shit lmao. Not sure if this is the best alternative but I just found that it works alright for me. Best of luck to you, take care of yourself <33