Advice repair bathroom wall
after having looked a few youtube and read some articles, I am still unsure how I should address the issue I have in my bathroom.
I just bought a condo built in 1990, and after a few days I noticed the wall being swollen and some tiles were moving if I press on it . I removed one and found out the drywall is very soft/squishy and a bit of mold is visible .
Only the larger wall is impacted.
I talked to a few contractors but this job seems to be within the 5,000 mark and as I just started paying off my mortgage, I don't have this kind of money right now.
I know the best would be to take all 3 walls down and replace with proper waterproof board ( maybe insulation as well) them retile . I am not opposed to try a DIY here but it seems scary , and especially I can't find what exactly needs to be done .
Is there a good solution , maybe intermediate that can be both cost effective and efficient ?
What would I need exactly to get started ?
I appreciate the guidance as I feel like running in circle and not knowing where to start or what the scope would be. really .