Our house smells like moldy pee after a bad ac filter not cleaned for years, how can I get rid of it?

The filter is right under the unit & we pulled it out to see a tray full of nasty black gunk. I tried spraying lysol into the intake, it didn't last long. Most of the smell is in the front of the house and I have bad allergies & asthma. Someone please help with a cheap fix, we don't have much to spend .I think there is still mold somewhere because my eyes/nose burns. BJ in LA Thanks You for any suggestions, ideas, etc.Also how to get your husband to admit he was wrong about it!!!!!