Who am I?

Who am I?
i once thought I was me,
what happened?
I look the same,
well....almost.

But I feel,
different,
sad,
depressed.
Is it me?
well...
It may help to know,
Who am I?

I couldn't have been,
happy,
energetic,
talkative,
person.

I understand,
people change.
But I didn't change,
I couldn't have,
could it?
If I have,
who am I?