Try moving the rook to e1 and then when your opponent tries the bishop trade to weaken your kingside, you can move the bishop to h8.
Remember, even if you don't have time to "move the Rook from its castled position" It is better to waste a little time to secure your kingside and keep your king safe instead of losing the game completely.
I hope I was of help to you.
Okay, I played the Sicilian Dragon as Black yesterday, and White responded with a (modified - it was slightly different)) Yugoslav Attack. White later played the annoying move Bh6, and I did not have time to move the Rook from its castled position, so I could not retreat my bishop to h8. After I finally decided to exchange bishops (with the Queen coming it to take my Bishop), White won the game with an h-pawn push and the Queen lodged nicely at h6, before I could even work on the Queenside! So, how should I defend against this threat? Should I leave it alone and let Bxg7 Kxg7 happen? Should I have moved the Rook earlier?
Here's what I mean:
Actually, in this case, I could have done Ng4, attacking the Queen, but my Kingside would still be weak.