There are a couple of ways you can handle this
1: Rip it all out to the studs
2: Hire it out and pay your life savings, because God forbid we do anything ourselves anymore.
3: Burn it all down and start over (I wouldn't roast any hot dogs in that fire though)
Option one is probably your best solution. Once you've got it all ripped out now you want to spray it down with stuff worse than acid..j/k...don't do that. Household bleach is not good enough. A good choice is outdoor 30 second cleaner at the big blue and orange stores. Once sprayed, Don't breath in those fumes! Next you want to dry everything out. If you don't dry it all out, when you build it back you might enclose moisture in certain areas that can't escape. Years later, you'll be back to square one. Steps on drying everything out? How do you know when its dry? A moisture meter is your best friend. It takes out the guess work. It will tell you if the moisture in materials is ok, mid level or too high. Also a Thermometer will tell you how much moisture is in your air. If you dry your materials out and there is no airflow it's all coming back. (Fun fact in our high humid environment: did you know that some old plantation builds used to plant trees in rows alongside towards the house in order to direct airflow through the home when windows and doors were open?) Fans and running the HVAC system can dry your place out but the best way is to buy a dehumidifier. It will collect water from the air and then you can dump it outside. Once your moisture meter checks ok everywhere than its time to start building it all back. Cheers!