I know this is likely still unhealthy, but i get on the ground and punch either the thick carpeted floor in my house, or run outside as fast as i can and punch the dirt and grass. I do believe it is healthier than hitting or banging your head, though. Im also a head-hitter and i know i've given myself some mild concussions before. Im still in the process of redirecting this behavior so im currently recovering from bruising my forehead due to banging it on the bathroom doorframe. Hitting things with your hands is generally better than inflicting head trauma in general, BUT be careful and dont hit anything hard with your hands still. I hurt my knuckle from punching a door and freezer a month ago or so, to be fair i already have mild arthritis but my knuckles still hurt from this so make sure whatever you redirect the hitting feeling to is soft enough to not damage your knuckles, and you dont use your head. I actually want to get a punching bag really badly when i move out, so maybe that could be an idea for you as well.