Them I made withdraw (for 5BTC) to a wallet address that I had set up using Armory
If you happened to have copied Armory chain code and root key somewhere, you can recover your private keys without Armory at
http://brainwallet.org/#chainsOtherwise, make immediately a copy of your armory directory (~/.armory if you're using Unix). It contains your wallet data, and I'm sure Armory's author will be able to help you if there is anything to be salvaged here.
And
after making the backup, update bitcoin-qt to the latest version, this is a known bug.
Then start the new version of bitcoin-qt and have it reorganize the database. Unless you have a backup of the bitcoin-qt data directory from before you started, then restore it before starting the new version of bitcoin-qt.