It sounds as though your heater core is stopped up, have someone intelligent to drain your radiator and catch the antifreeze because of animals drinking it, it will kill the animal, then flush the radiator & heater core with a flush designed to cleanse the system, follow directions from flush manufacturer, then put the correct amount of antifreeze in your radiator. Wal-Mart or any parts place will have this in different brands. This may help, it did on my 1998 mercury Mystique.i hope this helps you
P.s. Just follow directions on the flush container & this can be done by the do-it yourselfer
Make sure you allow the engine to cool before pouring the new antifreeze into the radiator, could burst your engine block.

Also check your heater control valve, turn every thing off then turn the ignition to the ON position now be quiet and turn your heat to cold wait a few seconds then turn it to hot quickly and you should hear the valve open to release hot coolant into your heater core if it doesn't make a sound have someone look behind the engine on the back fire wall while you move the temp control knob and they will see it it has two hoses one comes from the block and the other one goes into your car :) good luck, this is what was wrong with mine