mold on living room walls & doors

There are mold resitant paints and additives, Your paint store would best direct you, But first you must kill the mold and wash it off, painting over mold will only bring it back and as it will be sealed under a layer of paint you will have worse problems. Regular bleach kills mold, I use a spray bottle or garden sprayer. Then wash it off with a strong soap, TSP. The easiest way to control mold is regular spraying of bleach , before it grows much. Mold is everywhere.

The problem is that the warm side, while wamer than the cold side, is a lot cooler than the rest of the warm room. The best way to fix that would be to insulate the wall in question. The reduced cooling costs should pay for the work in about 70 years. Barring that, I think you're stuck with washing the affected wall, periodically.

Leaving a fan such as a ceiling fan running 24hrs/day helps. Consider running a small window AC unit (5k) continuously in the other part of the house. It is cheap to run It will be just enough to keep the mold down and provide a bit of comfort.

Insulate that wall and wash everything down with some bleach followed with some new paint with an anti mold additive. That last part is dependent on finding some recommended for interior use. Some may be harmful to children.

Don't forget a vapor barrier or you will have mold inside the wall.