Re: fungus:
i think first two probs are with our bathroom
pipes leaking.....
rain water
you have to fix the cause of it before you can fix the look itself.
do you have pipes leaking in the walls and ceilings? do you have a leak in the roof so rain water is getting in the walls. is there not enough ventilation in the bathroom? do you have moisture problems somewhee else e.g.
Please do not just, clean it and cover it up with new paint or something, have someone come in and do an assessment.
for immediate short term fix and to avoid it from getting worse. clean the moldy areas with special cleaners you can find in home stores
make sure you ventilate the place thorougly, and I would suggest getting a dehumidifier for the bathroom for now.
but this is just a bandage, you need to figure out what is causing it in order to be able to stop it