Alternatives to self harm for regulating emotions?

I need some ideas for how to deal with my meltdowns without self harm. I have been trying not to punch my head or face lately (genuinely worried i might do damage), but instead I bit myself on the arm tonight and I think it is going to leave a very obvious and embarrassing bruise.

I don't understand why I have such an extreme urge to hurt myself, but at the time it seems like the ONLY way to get my emotions back to a slightly more balanced place, and I hate how out of control I feel when I am having a meltdown.

I am trying to figure out some alternatives that give me the same feeling without damaging my body, while still being enactable mid-meltdown.

Does anyone have any suggestions?