That is the problem. Too much of a good thing (mild winter) makes the plant go soft. Sometimes we need to simulate the harsher conditions to make the plant hardy. In the wild, natural selection would just kill it off (the strong would survive).
That is why drying it, more light, and letting it reduce temperature (while dry) will actually help it get better. That is the theory anyway. If it doesn't bounce back, then it could just be a weak plant. I've had those too. After frustration with trying to "save" them, I finally wised up and tossed them.
Happy New Year!!