It's bad but not the end of the world.. Don't put the key in the ignition. I'm not familiar with the connections for the electric water pump but you should look into it and disconnect it for good measure. Then I would get a vacuum pump from a local parts store and suck out as much fluid from the coolant tank as possible.. If you're not able to get a whole lot I would work on pulling the tank out. Oil is lighter than coolsnt but hopefully not much oil had gotten into the system through gravity. But a complete coolant system flush might be in order.
Or get the car towed a reputed shop and explain what you did.. Whatever you do, please ensure the engine water pump doesn't run..