Iveco 75E15 lost power and now wont start?

Hi,
my 75e15 has been running fine for ages, then it developed a vibration when below 500 rpm. but seemed fine.

Well today i was driving (about an hour) & i thought i was loosing power. When i took my foot of the throttle and put it in neutral the engine nearly stalled, but recovered when i used the throttle. Then when it go down to 300 rpm I could not get it to accelerate the engine (no load).

Now it wont start, cranks fast and no warning lights.
So it has fuel, temp was in the normal position, oil pressure good.

Any ideas?