my ford ka just suddenly went loopy on the motorway yesterday, the acceleration has always bin pretty bad, only going 50mph up a hill on the motorway or 20 on normal roads, but now something has gone wrong, i was going down m6 to birmingham from the north like i usually do with the car, but all of a sudden it felt like the acceleration had failed, it went down to 30-40 mph on the motorway going up a small hill (had it in 3rd gear but still would not accelerate) it felt like it was stooling and pulling me back. it wont even go up a small hill locally now - it went down to 10 mph in 2nd gear i had to put it in first gear. how embarassin. can someone please help let me no what is wrong?