If his own reaction and Ginny's reaction had been less extreme, he might not think himself evil. Nor would he if he heard about it secondhand. But that's part of the reason he blasts Hermione for not being there; he can't really explain the intensity of the emotions, but he knew he felt them, and he never wants to feel anything like that again.

To Harry, that he stopped himself doesn't matter, because he so nearly didn't.

Thank you! Draco definitely will stop taking the Desire potion.