Why is my hondda overheating and heater not throwing heat when it does overheat?

It's obvious it has a leak at some point. It really needs the cooling system pressure tested at a repair shop first.

The head gasket failure is such that it will force exhaust gas into the cooling system. A common symptom is that the radiator will be partially empty, but the coolant overflow reservoir will be completely filled (the exhaust gases push the coolant out of the system, in other words). Overheating without any leaks is another symptom. In these 7th generation Civics, this type of head gasket failure is common and you won't often see the usual symptoms of coolant and oil mixing, or white exhaust emissions.