need help dont want to lose my landy

hi all new to land rovers previously had a hilux, love my 200tdi disco, went on my first off roading expedition yday to sarn helen, on way home towed a series 2 out of petrol , all of a sudden engine is steaming with smoke, blew a massive chunk of smoke out of exhaust. opened up engine and when you turn engine on lost cap to coolant and water is spraying out.
is it the head gasket blown, have only had car two weeks and i have spent 2 grand on it so far, anytips i need to fix it cause i dont want to end u having to buy an sj or frontera that are rubbish, i want to repair this but dont know where to start, any help would be greatly appreciated.
thanks

mate post in disco section asap, theres a good bunch of experts on here witch i bet my landy'l know the answer.