Well I hate to say it, but it sounds like it might take major repairs if the mold has done enough damage to where the bathtub nearly fell through the floorboards...those would for sure need replacing, mold would need to be removed and any other damage its done may need repairing though the floor would be the most important so things don't fall through.
Do you or your ex(since from the sound of it you still live together) know any friends/relatives/aquantinces that know how to work on houses and might also have a gas mask or something so as not to breath the mold while removing it? who could maybe help you out? Or do either of you know how to do repairs? That would save some money since I imagine hiring people could be pretty pricey, either way though for your health it needs to be taken care of ASAP or moving might be the only option, a lot of mold like that is toxic to an extent at least.
_________________
We won't go back.