After I've completed the majority of the quest, going back to Riverwood. A dragon attacked the city, and while I was fighting the dragon I accidentally hit Delphine... Now whenever I try to talk to her to complete the quest she attacks me automatically.... Any help/tips are greatly appreciated since I have 80 hours in already.

Sigh, seriously...Ok, sorry for being rude.

But did you seriously IGNORE the stickies on this section? I see that this is your first post (which pisses me off a little bit more).
No spoilers no nothing on this section, and don't tell me that you actually missed the cheat, hints & spoiler section/HW & SW issues on your way to General discussion....

Reload a save from before the attack?