Tugg
YIKES , no wonder why your sick. Bathrooms are relatively easy to remediate because they can be contained so easily while remediating. If it was my house I would have already had the entire shower tore apart put new mold resistant dry wall in and replaced the tile. I'm sure YouTube has videos that show you how to tear out the old drywall and install new drywall with new tile and all the tools your going to need Just remember to put some 4 mil plastic around the door to avoid cross contamination