It's probably broken. You should see if you can get a mechanic to look at it for you.
the coolant level
how do you fix the heat in a 2002 Chevy impala
The fan is not working.
Assuming the blower motor is working, it could be low on coolant, a stuck open thermostat, a plugged heater core or a faulty temp blend door actuator.
95 Chevy impala egr valve removal
The older style impala SS had kits available to do this. 1995-1996
Click the link.
You need to check your thermostat, pretty cheap fix
Quite possibly the heater core is bad
The heater isn't an extra unit, it is simply pulling heat from the engine and blowing it into the cab. If the engine is not hot the heat will seem like it is not working. If the heat is not working after the engine has warmed up, you may have a fan that doesn't work, or a clogged vent.
Sure it's a Buick?
There are several places that a person can get interior door panels for a 1995 Impala SS, including a junkyard. A person can also check online or at body shops.