hot cooling!!!

i was driving today on the highway when i saw my temp. gauge very higher.it was almost on the red line.i pull the car and stop the engine.i lifted the hood and i saw a lot of my cooling stuff coming from the water tank.i don't know why because i never over filled that tank.i waited a few seconds i started the engine again.i saw the temperature on the gauge starting to lower.now,my water tank is empty.i have to fill-up.what do you think it could be?? this my mod"s on my carulley,headers 1 5/8,magnaflow cat-back,gt-40 iron heads ported,thyphoon lower and upper intake,24lbs injectors,70mm throttle body,e303 cam,mas air flow,cold air intake.is there a way to check if my problem coming from the head gasket??also i think that my cooling system never been flush.i don't know if it could help but sometimes when the car is not running,my temp gauge raise a few and when the car is running,the temp gauge lower.thank's!!!