Is it more correct to say "I am only me" or "I am only I?" I know that the subject should follow a linking verb like "am" or "is", e.g.: "It is I", but "It is me" is also correct by common educated usage. So this matter of "I am me" or "I am I" is confusing. Which is more correct?
Generally speaking, when you are referring back to yourself as a subject, it were better to use "myself" instead of "I" or "me":
I am only myself, a mere mortal.
To give an example of why "me" is better not to use, consider that "I" is to "We" as "me" is to "us". To say
I am me today is like saying
We are us today or
They are them today. It were clearly better to say
I am myself today,
We are ourselves today, and
They are themselves today.