Engine overheating and A/C is not working properly

Okay, first I'll start by saying that's not the actual miles on the motor.

But anyways, this is my wife's car about a week ago she comes homes and tells me her A/C quit working. And that it will blow very little cold air so I pull the blower and it works great I change the resistor. The control module seemed to be working good. So I put everything back together we take a ride to town with a good cold working A/C only to get about 5 miles from home and it just quits. So I pull it all out again and notice that there seems to be a short in the wires to the blower. But she had to have her car to go to work before I could fix that. Well she comes home today and the car is getting hot, plus what little if any air will come out of the vents it's so hot like the heat is turned on. Plus now the security light is on and staying on on the dash and on top of all that it has drunk a half tank of gas today and it only went 20 miles I doubt it's even been drove that much today.
So my question Is where the heck do I start? This is the only vehicle we have running right now and we have to have it. I'm currently on the hunt for a transmission for my truck so we sure can't afford to have the car down on us too.