Rapid misfire and smoke

[HomerSimpson]

Help!!!
While travelling home today on the motorway my A4 1.9 TDI suddenly developed a rapid misfire and spewed white smoke from the exhaust, as I slowed down the oil light came on. I suspect that the head gasket has blown big style. Whilst waiting for the recovery vehicle I noticed a small pool of oil on the ground, about the size of a clenched fist. Am I correct or has the engine blown altogether?
Any help gratefully recieved!

[HomerSimpson]

Update.
Oh Dear!! It would appear that one of the con rods has given up the ghost, causing the piston to hit the injector and smashing it, also the valve stem and camshaft have been damaged. So now on the look out for a new engine.