I did this quest and it dropped my reputation with them to "Shunned".. Now they sent some lady who said I have 3 days to improve my reputation with the NCR, otherwise they send goons to come kill me. I've done 3 quests, 1 of which improved my rep, but it didn't change from being Shunned... Is there any other way besides doing quests?

DOOOOOOOOOOOOOOOOOOMEDDDDDDDDDD



=) do more quest?

Go to "That Lucky Old Sun" at Helios One and that should greatly improve your rep with them. Then help with some Mccarren Airforce quests, more rep gain. Then after that just help some different places like Mojave Outpost and your rep by then should be neutral or accepted. Hope it helps.
Also make sure not to use the "wait" option or else your time will go quickly

This really svcks i dont want to go back and lose 5 hours of gameplay because stupid companion ai decided to help CL kill a NCR patrol, now im at hate and no way to get out of it.. i got quests for ncr to turn in but cant get to the npcs without being facerolled -.-

Lol I have this exact same problem I figured Boone couldn't handle troopers so I sent him to the 38 Casino and I headed to the Legion camp(Boone can't follow me there without killing people so that is part of the reason i parted with him)I figured that while at this legion camp if the troopers try to kill me they would have to go through Caesar himself