The furnace was installed

I am sick of cleaning the inside of our cooling unit. Every month there is something new & disgusting in our A/C unit. No matter what I buy, install or have the HVAC professional do, the a/c is regularly gross, first, the air filter on the unit is regularly clogged with dust. I heard that the a/c filter can be changed daily. I do mine every 2-3 weeks because I can’t sit the dust inside of it. I thought buying a HEPA filter would be better. Nope, I legitimately had to change the air filter more. Next, I regularly have some sort of fungus growing inside of the A/C device. There is regularly mold on our cooling coil. I heard that installing UV lights would help this issue. I installed Ultraviolet lights & the mold is still quite prominent in the undefined plan. To make matters even more sad, periodically I have mold all over our lights. Another issue is the condensate drain with the cooling unit. The drain is regularly clogged up. It usually clogs with algae. I regularly know when it is time to clean the drain. There is a substantial puddle of water all around the A/C system, staining our carpet. I then open up the A/C & muck out the drain. I hate that job the worst. What can I do to keep the A/C unit clean? Is our lake house abnormally dirty & this affects our A/C equipment? There must be another step I can take to ensure the cooling unit is not gross.

gas heater