02 oldsmobile intrigue running hot losing coolant from tank

I have 02 oldsmobile intrigue and my resevoirs seal around the middle of the two molded halves is leaking somehow… i can feel my engine is running very hot and I’m going through coolant n water like crazy… the temperature gauge really only goes up once my coolant is low… I had the water pump changed at a place right before this began… would this break in the seal cause temp problems?like coolant is boiling right away and puts off some serious heat… I also hear popping in heater core once I fill the reservoir all the way up. Most coolant is evaporating cause only leaks through seal once it’s filled passed that mark… I was gonna try to sell around reservoir with a bonding agent if that could be effecting the pressure and temp. Also when accelerating at higher rpms temp goes down…any ideas what could be causing this… or why seal on reservoir would start to leak in first place, if it got that hot I need to address that too.

Yes, this will cause overheating. You MUST replace that reservoir first thing if you want to stop the overheating and coolant loss. It cannot be repaired.

Because it is plastic and 18 years old.