hi hope you can help. my alfa broke down on me

i was driving slowly having just pulled out of a side road. suddenly there was a bang a rattle the car pulled to the left then wouldnt go forward. I had a look round the car and could not see anything wrong so started car up again tried to go forward , there was a load of clunking then would no drive at all. had another look under car and it was leaking oil really badly from the front seat position area. it starts but just revs and gears still all go into gear. please help. It is stuck at the side of the road, I am a mobile carer and NEED my car to work. thanks