Remove grammatical mistakes: Then I've got new one, so I decided to take my old iPhone to bits!
The first sentence is correct, but the second one is wrong.

I'm not sure if I'm doing this right, but I'm not sure if I'm doing it right.

I'm not sure if I'm doing it right, but I'm not sure if I'm doing it right.

I'm not sure if I'm doing it right.

I'm not sure if I'm doing it right.

I'm not sure if I'm doing it
The first time I saw the word "the" in the sentence, I thought it was a mistake. But after I read the sentence again, I realized that it was a mistake.
I think I'm sorry, but I'm not sure if I'm right.
Correct: I'm sorry, but I'm not sure if I'm right.
I'm sorry, but I'm not sure if I'm right.
I'm sorry, but I'm not sure if I'm right