17 month old ?

Ok so my 17 months old is so different to his older sister he walked early and he never talks he use to when he was younger he wouldn't stop but now I can't even get him to say mum :/ he also likes to be wrapped for bed time when its cold I have never seen a 17month old getting wrapped for bed and he walks on his tippy toes and headbutts everything that hard door ways tables hard toys and he will do it again and again till it hurts that much he screens and that's with out having a tantrum when he has a tantrum is 10x worse I'm lost as to what to do someone told me could be artistic but I'm not sure I don't wanna go to the doctors and ask as I would feel a little silly if nothing was wrong could someone plz help me with Wat this could be plz