1993 Chevy Cavalier 1993 Cavalier overheating

I have a 1993 chevy cavalier that is overheating. It leaks coolant from where the heater core is. When the engine starts to warm up, steam collects on the windshield. When you turn on the defrost, you can smell anti-freeze. I was told it was the heater core but its still blowing hot air. Any suggestions would be greatly appreciated thanks.