amn’t is an incorrect contraction for am not. Ain’t is the correct form, but grammatically incorrect (go figure??)

The question: “Do you know who I am?” could be beligerent, like “How dare you say that to someone like me.”

Alternatively it could be a child talking to a parent with dementia; a kind of “Do you recognize me?”

The negative form actually asks the same question: “Don’t you know who I am?”

The answer: “Yes I do” can apply to both questions which is interesting. Likewise the negative answer: “No, I don’t.”

Looking at the examples you give, none are grammatically correct. How about: “I’m not who you think I am.” Or, in more subtle fashion: “I was never the person you wanted me to be.”

It’s like a soap opera, isn’t it?

You could have fun by extrapolating this to a great degree. For example: ” You and your Papa set me up as this character that would just do everything you, she and the rest of your clan would want.

“But y’know, I’m not like that; you misread me right from the start. I am not a toy to be played with.

“I’m going back to Mommy and my little kitty, Peskie, and we’ll just be as happy as clams back in Macon, Georgia. Besides, I gave my Barbie dolls to the orphans at a church charity sale, so there.”

Isn’t grammar fun?