Sorry, not a good sign that your coolant levels are low, if they were normal before this happened......if enough coolant is in the exhaust, it could actually block the exhaust and choke the engine......
What I would do is get a coolant pressure tester, and pressurize the system overnight.....next, remove the plugs and disable fuel and ignition(disconnect injector harness and remove power from the ICM[two wire connector on the passenger side])......then have someone crank the vehicle....if coolant comes out of any of the spark plug holes, chances are you have a head gasket/head problem.....