Gosh! It's none of his business whether you need to grow up or not! It sounds as if he's just a bully who likes making people feel bad, so you should really change the job!!! Really!

Not only is he being mean to you but he is also abusing his position of power to treat you in humiliating ways. Don't even consider looking for faults in yourself. You might have plenty of them but it is NOT your boss' business to judge your personality. If he's not happy with the work you are doing - he can just fire you, not make a fool of you.