Have you checked your coolant since you refilled? If it's gone down, you're in for some problems because you're either leaking it, or burning it. Also, make sure your radiator fan is turning on when it starts warming up. Since it started after a slight accident, I'd have your coolant system checked by a professional. Also, drive it as little as possible in this condition. Overheating can do horrible horrible things to your engine. If I were you, I would just drive it straight to a shop and have someone check it out, if you're not sure what the problem is.