99 Sunfire GT engine knocking, smoking white and leaking oil. Now wont start, just makes clicking noise?

After driving my 99 sunfire GT convertable with a 2.4L 2L twin cam engine, I had jumped onto the free way and before even getting down the entrance ramp, the car began to rattle really loud like a loud repetitive knocking. The car lost speed and I was forced to pull over tho the side. A cloud of white smoke puffed from the engine and everytime I turned the car on more white smoke came from the back of the engine, (my guess coolant but it was dark outside). I managed to drive her up the exit ramp only being able to go 40 and parked her in a gas station to await a tow truck. After getting back home I was suprised to find that the car had leaked oil on the tow bed and when I parked her in the garage she was leaking oil as well. After looking through the engine the following day she wont even start. Instead she just gives this clicking noise. Any ideas what im looking at.

oil seemed to be around the spark plug ignitions, cant seem to see if the oil is coming out of the oil pan or another part at the bottom, Next door neigbor (used to be a autotechnician at chrysler) says its a valve problem. Car was bought used but ran perfectly the week before the break and drove perfectly all day before the break.