So I am on "For the Republic, Part 2". Or at least that what it says. I just got the quest to go blow up the BoS. However there are a few problems I have run into:

1: I have ousted Elder McNamara, and am a part of the BoS. I can't find McNamara to get the 3rd key card.
2: I saw in another thread I made that I should still be able to tell the NCR that the BoS is with me. So my question is, how do I do that?

So I can't find all of the key cards, and I can't get the dialog to show up to tell the NCR that I am with the BoS. Oh and I killed Mr. House at this point (obviously). I can't advance in the story line anymore, where to from here?