I actually fixed the damaged area couple of months ago but I forgot to update here but this is somewhat important for me so I won't repeat my mistakes.
So for 7 years since I've started living in this apartment, I haven't done any home improvement or maintenance works because I have no skills whatsoever so one of things I've promised myself to do or start doing is to clean my apartment regularly, stock up my fridge with healthier food, less caffeine consumption and fix my mold infested walls.
After cleaning the surface dirt and dust, I removed the mold with mold removers that I got from Mr. DIY then left the wall to dry for several hours before starting applying or more like sealing the cracked areas with putty filler cream and then leave it to dry again.
So the above is after applying about 2 KGs of putty filler.
I've noticed the cracks formed after the areas dried out so I added some more fillers mixed with less water this time.
The above is after everything applied has dried out so I guess that's considered done unprettily but that's okay as I'm planning to repaint these walls before Raya anyway. What matters is the wall is fixed and as seen in the first photo above, the rough textures are not that noticeable so all is good, at least for now.
The thing to remember before doing this again next time is to adjust the water for the cement compound accordingly or maybe just get the instant putty filler. Also, get bigger scraper for bigger surface areas and last but not least, to cover the underneath area properly with plastic because it's quite messy afterwards.
