Reads like a few problem not just one.
Remove radiator cap
let it idle
Feel the upper radiator hose, should be cold.
After idling for 3 minutes feel upper hose again, should still be cold, if it is warmer then thermostat is stuck open.
If still cold let it idle a few more minutes, thermostat should open after 5 to 8 minutes and upper hose should start warming up.
If, after first starting, coolant starts coming out the rad cap opening then you have a bad head gasket or cracked head.
If, after idling 5 minutes coolant starts to overflow then you water pump is most likely bad
How old is the timing belt?