1999 Jeep Laredo

I have a 1999 Jeep Grand Cherokee Laredo, with the inline 6. A few days ago the air conditioner just stopped working inside the car. The lines running from the condenser to fire wall are ice cold, but inside the car, there is no difference between the outside air being on and the air conditioner being on. When you press the A/C button, it sounds like nothing is happening, even though button lights up. I checked the A/C clutch relay and fuse, even changed them out, but no luck. Any other suggestions? I read somewhere about doors that are in the vent system that break, could that be the problem? Any help would be huge. I'm in law school, in florida, have too many loans as it is, can't afford to go to the shop and its ridiculously hot this time of year. I'm pretty handy around cars so I can fix it myself, just need to know what/where. Thanks in advance.