What is this song called....?

Okay, so this song has been stuck in my head for a while now, and I don’t have a clue who sings it. It’s just this same verse, again and again.
“Now that I’ve realizes that I’m going down
From all this pain you’ve put me through”
and then it says
“I can’t go on not loving you”

it was from like, 2004 ish? I was pretty little when it came out.

If anyone could help, that would be GREATLY appreciated!