White smoke from exhaust

When I start my car, once it gets to operating temperature, white smoke starts coming from my tail pipe continuously, and if I press the gas the white smoke gets cloudier, I was thinking head gasket but the car doesn't overheat at all. I am not losing any coolant, no milky oil, car is even drivable, except it is not because of the white exhaust smoke. So I am clueless as to what it could be, I been doing some "research" and heard it could be a bad fuel injector, could that be the problem, I do get a P0300 once diagnosed, is the the code for a bad injector? It is driving me nuts. I do not want to get a head gasket repair if it is not the gasket. I even did the "engine block test" and fluid did not turn yellow, it stayed blue. Could it be that my even is just completely done? I hope that is not the case.