right if your head gasket is gone
undo your oil filler cap on the car if it is creamy colour
good chance head gasket, if it's black its ok
as for the driving home after fuck fit
check your spark plug leads are pushed on properly
they could have messed with the timing
also asked a decent mechanic to do a compression test on the engine
if the head gasket has blown take spark plug leads off one at a time
start car listen for a different sound
if you removed a s/p lead and the car sounds the same
head gasket could be fucked