Kitchen Large Electric Appliances - Wall Mount AC condensation

My wall mounted whirlpool ac is leaking condenation in the space the unit occupies in the wall. There are no holes, its just forming naturally on the bottom of the unit. Problem is this condensation accumulates and starts dripping down the wall, ruinning my paint. I don't understand why its doing this, how do I fix it? The unit is installed tilting down (forgot the # of degrees) down, to allow the water to drain outside, but its still draining inside and defeating gravity.

The wall mount is what was in this home when we bought it, and there literally is NO other way to chill this house. There is no means of putting an ac in a window. and there is no forced air furnace for central air, and no mean of installing a forced air unit. So any advice on resolving my current situation would be wonderful!

One thought I just had about an alternative cooling unit, we have a hot water boiler system for our heat, is there a company that makes a water chiller that would do the same thing? But circulate it around the house like the hot water? Or would that just mean more condensation in a alot more places?

You may want to look for a thin piece of rubber that you could cut and install on the bottom of the pan inside the unit. You would have to make the corners watertight also. Can be done though. Good luck.