Haha no I'm the idiot for posting when sleepy. From what you said it seems that there may have been something you added to the tank in too high a concentration. From my experience, mollies may act that way when salt is too concentrated or the water is toxic (by adding wrong salt/not dechlorinated), or something did get to the swim bladder.
If your mollies rest on the bottom of the tank or float at an ackward angle, quickly shoot upwards (as if going to gulp air), swim erratically and quickly across tank, sometimes bumping objects...
These things would make me think it may have been something simply wrong with water before disease.