1996 Toyota Corolla Car overheated and heater blowing cold

I drove my car yesterday and I noticed the heater was blowing cold air. A few minutes into my 30 mile drive my car overheated and killed. I checked my oil and water, and as a typical girl realized that it was nearly empty. I filled both my oil and water, let the car cool off and continued my drive home. Almost home I decided to turn on the heater to see if it would blow hot air, not even 2 minutes after I turned my heater on my car got overheated and killed again. What do y ou think the problem is? Any help would be greatly appreciated.