fan making terrible noise then fell out help major trouble

Hi drove my beetle home last night and sounded more noisy than usual, then became really loud and in intermitant almost like a breathing rythmic grinding sound statred happening and also as if it was sucking in air (like on a windy day) Then started accellerating without me pressing the pedal.turned off to a side road and pootled at 30 which seemed to be a bit better then noticed that there was smoke in the car. Turned car off almighty grinding, and running really fast when i looked under the decklid the coil had come off the fan housing as i had been saking so much. didn't dare start again, so pushed 2 miles home
Looked and the fan had disconnected itself, why would it do this have a done a lot of damage/can it be fixed easily.
Never had any probs but seems just lately everything is going wrong.

ps am a novice so please speak in stupid terms
Thanks in advance