1.4 16V P0300 Cylinder Misfire HELP!

So I was driving home today when my oil warning light came on (No big deal as this is a frequent thing due to an oil leak i haven't investigated yet) about 40mins later I was about 100 yards from home when the car started juddering and my engine warning light started flickering on and off. At this point I knocked it into neutral and coasted onto my driveway! and switched it off. I left it for a couple of hours for the rain to stop!! (Could be a cause as i have no undertray?!?) I topped up my oil and took it out for a drive to see if it cleared the engine warning light. It was succesful till roughly 20mph when it started to really judder like it was about to stall but instead kept accelerating!!

So i turned around went home and plugged my scanner in and got the code 'p0300 Cylinder 3 Misfire' deleted the code and started the car (Just to make sure it wasnt an old one) then re did the scan and got the same problem!! random multiple misfire and cylinder 3 misfire.

Has anyone else had a similar issue and know a quick fix?