lost power

hi, on saturday morning, i was driving down the road when all of a sudden the car started to drive funny. the gas pedal seemed to be almost 1/3 to 1/2 way down and the car seemed to be losing power. i switched it to neutral and the revs shot up to about 2500 rpm. when i switched it back to drive, it continued driving funny. thne when i pressed the gas, it stalled. i tried to start it but it wouldn't start. 2 mins later i tried again. about 5 minutes after i tried again and it started. what could be the problem?:confused:

2004 octy mk1 estate 1.6 ambiente