Fallout New Vegas Vilified NCR?

So I have loved the Brotherhood of Steel and Enclave throughout the Fallout series, BoS is my favorite by far. So in FoNV I want to be a part of the Brotherhood of steel. I completed the quests, and I am a member. McNamara is still elder. I am Vilified by NCR. I cannot reset my reputation because 1- All boomers are dead 2-I am shot on sight. So I either have to ignore the BoS(D:) or complete the quest to make the BoS sign the treaty. Only problem is I'M VILIFIED... I'm going to try to get in wearing NCR disguise... Please respond fast.