I would say your engine is toast. Sounds like the engine has "runaway" on its own oil. not good news.

Good morning, I noticed that there was a blow of white smoke coming from the exhaust yesterday and so; thinking it was the DPF I went into 3rd and rode the car for half a mile at 3500 rpm. I let the throttle go but the engine speed went up to maximum, I pulled over and turned the ignition key to off but the engine kept running at maximum , still blowing out white smoke for about 5 mins. the coolant was blown out but there were no signs of oil in the water or vice versa. The car start with reluctance and seems to lack power as if it is only running on 3 cylinders. Any ideas?

Sounds as if it ran away on the sump contents: probably some damage which only a strip down will confirm the details of. How much was left in the sump after the runaway?