A Subtle Miss

Black black to play, White just played Rg4-Rg6. We are in trouble. We're down one pawn, and probably will be more, and I will be helpless once the b5-pawn and a4-pawn run up the board. I played 46... Nd2+, hoping for something out of nothing. Feel free to take the position above as a tactics trainer... rated, ohh, I don't know, you discuss in the comments!