"Do you think I'm happy about this?" Elena demanded, barely able to see him through the tears, though she certainly glared. And looked very miserable.
"I can't bear the thought that I hurt you as much as I did. You have been nothing but sweet and kind and generous and....I thought you were the only good thing about me moving to Starling." And then she'd gone and messed it up.
"...and if I've fallen so far in your eyes..." There wasn't really any use to her staying around. "You'll never forgive me. And...I can't forgive myself."