Water dripping (almost running) out of the left corner of air handling unit. Help???

I have a Ruud Air conditioner/gas heater with the furnice and air handler located inside in my utility room with the air handler sitting on top of the furnace. Last night I noticed that it was not getting quite as cool as it should be getting inside and the air conditioner kept running. I checked the filter and it was black & soaking wet! I just changed the filter about 4-5 weeks ago. I changed the filter again. This morning when I got up I went to check the filter to make sure everything was lookin ok, only to find water all around the unit on the floor. After watching the unit a while I discovered that I have water dripping (almost running) out of the front left hand side of the unit. I went outside to the condensation pipe and found that the condensation out-put was not as much as it usually is. The pipe appeared to be clogged with brown and slimmy gunk. I took a clothes hanger and cleaned the little "L" pipe out the best I could, which is only about 7-8" long before the pipe takes a 90 degree turn through the wall to the unit. The tempatures here for the past couple of days has been over 100 degrees and the same is predicted for today (current time is 1:03am). The water dripping out of the unit seems to getting worse. I have a dog and 2 cats, not to mention myself, to try and keep cool, but I have been forced turn the unit off until the dog starts panting. I have contacted several HVAC companies, however, with the high temps they are currently booked for a few weeks. A few minutes ago I felt the air handling unit and it feels cold to the touch. Any help, information, and/or suggestions as to what I can do on my own until I can get a professional here to take a look would be greatly appreciated. What would be causing this problem? Other than the water issue the unit seems to be working fine as far as cooling the house. Thanks. Vanessa