My little boy bangs his head when he's teething, he's doing it again now and I noticed his molars are coming through. I try to ignore it as much as possible as he gets worse if we make a fuss. Current mantra is: he's doing it because he's struggling, he's not trying to be a shit
Head banging is a normal thing, its a way of self soothing. My youngest is 1 and does it, but out of my older 4 children my now 2nd youngest was the only one to head bang. Hope things get a little easier for you, it is hard for them to deal with all their emotions and feelings x