You might have oil in the cylinders as well who knows. Drain all the oil, pull out all the spark plugs take the dipstick, dip it in each cylinder and look for oil, if you have oil, then squeeze out all the oil from the cylinders. there is a little tool with a rubber ball on top with a little tube I don't remember the name, use that or a small pump and a pipe to suck all the oil. Let the engine drain oil for about one hour let it sit go have a cup of coffee. Clean and Install the spark plugs back on or use new ones if they don't look good.
Pour in fresh oil ( you can use the same oil, as it is new but I would not recommend, but just to make sure use fresh oil). This time make sure you add the required amount of oil only look up in your owners manual or online. Another method is to keep checking the dipstick and add oil accordingly. when you have enough oil in the car put the oil cap back on try starting the car. Let us know what happened.