Why does my a/c smell like antifreeze?

Hello, Sorry to hear that, there are a few things that could be happening. The first would be if you are sure it's an antifreeze smell you can bet the heater core is leaking. It and the AC core sit in the HVAC box and once it starts to leak you can git the small with AC but a lot stronger if your using the heater. On a cool morning it can even fog up your windshield on the inside. If it's not exactly like antifreeze, it's possible there is mold growing on the AC core, it's a real musky smell. The local parts store's sale a spray can with a long hose to allow you to spray into the air intakes with your cabin air filter removed that will kill this smell. While your at it change the cabin air filter. Good luck and have a great day.