NEW DEVELOPMENT!
I took my car for a spin (three tries to start it), it had no guts reversing up my driveway (has a gradual incline), drove around my neighbourhood for maybe 5 minutes, the temperature rose from half (normal) til it was over the "H" in less than five seconds. Coasted it home in Neutral, parked it, opened the bonnet, black smoke everywhere.. We got a proper light on it and there's oil in my cooling system but no water or coolant in my radiator, even though I filled it yesterday. There's also oil in two of the four spark plug tubes. You can't see the spark plug in the tube closest to the timing belt (drivers side) and it looks like oil has overflowed from that tube. AND there's water in the oil thing, I pulled the dipstick and the oil is that diluted it ran straight off.
We're thinking head gasket, could this be correct?
**EDIT**
Thankyou to everyone who's giving me advice and trying to help, it really does mean a lot to me. I greatly, GREATLY appreciate it. <3