I am no longer try to convince people I am important while secretly fearing I am not.
What is the role of 'I am not' in this term? Why didn't used 'that's not' instead?
I am no longer try to convince people I am important while secretly fearing I am not.
What is the role of 'I am not' in this term? Why didn't used 'that's not' instead?
What you have quoted is not grammatical: you mean I no longer try, or possibly I am no longer trying.
When you end a clause with not it is usually understood to be implicitly followed by something that came earlier in the sentence. So I am not is means I am not important.
"That's not" would not make sense here, because the thing whose importance is being talked about is "I", not some "that".