transit van 2.5 di lost power now wont start?

i was coming home on the motorway and i felt abit of viberation through the gear stick.{felt as if were running on 3 pots} got to some traffic lights and looked in the mirror to see it smoking abit dont no the colour as it was dark. came to a hill and i normally fly up in 3rd but had to get in to second got home and left it the night. came out in the morning and now it wont start? dosent evan try? any ideas any1?

craig