2 year old hurts self

My new to 2 year old has started hitting himself hard in the face, head, and pulling his hair. When I discipline him very lightly as in he smacks the iPad screen with a hot wheel I’ll just say “no don’t do that, it will break” and he goes berserk smacking himself. Like a penance or something, he’s very gentle with animals and other kids, and always follows my direction in these situations to be gentle. Even with me he’ll roughhouse a little and I’ll say be gentle with mama and he’ll kiss me. He’s rougher with dad but I think that’s in part because his dad turns it into a joke most times yelling something funny, or making a funny noise but even if he hurts his dad he’ll just say “ no that hurt papi” and he’ll kiss him.When he starts hitting himself it’s terrible he cries because he’s doing it so hard and I’ll try to hug him or block his face or head with my face or arms, even distract him. I even say be gentle with (his name) and say he’s a baby because he associates baby and gentle so well otherwise.Idk what to do. Idk what I’m doing wrong. Is this part of the “terrible twos?” Or have I already ruined this tiny persons life by inadvertently causing him to self harm. Am I overreacting because of pms? via /r/Parenting https://ift.tt/3o1E0Wp