My son hits and kicks me when he’s angry 😢

I have NO idea where he learned this behavior because nobody hits in this house. When he gets mad he’ll hit me really hard and if he doesn’t want his diaper changed he kicks my chest.

I mentioned it in a mom group on Facebook and someone told me “he’s too young to throw tantrums” so I thought ok maybe I’m just being sensitive but my grandpa saw and made a comment saying my boy would hits girls when he gets older and now I’m paranoid and don’t know how to fix it 🥺