Hello "whathappened".
This indeed seems like a Darksend denominations transaction. This transaction splits your coins into stacks of different sized, but it should by no means lose the coins.
When your Client loads up, it create 1000 addresses that aren't directly visible to you. They can be used by the client for various things, including Darksend (the mixing button you hit). It usually takes 0.0002 DRK in order to pay for this splitting, so if you saw -0.0002, then your client recognized the new addresses as it's own. If you cannot see or spent the coins, that means something went wrong.
The thing that went wrong is probably just a small bug that can be easily fixed.
First thing to try: start your wallet with -zapwallettxes and see what happens. Maybe this already fixes it.
You can also install the client on another machine, let it sync the blockchain and then import the wallet.dat from the problematic installation. Use another, older and stable version for this and you will probably be able to spent your coins again.