I've had my Christmas cactus for 15yrs and it thrived in the same place it's whole life. Right before I moved my mom stuck it outside forgot it over night I believe it got too cold and since moving it now lives in a window that only gets maybe 4hrs of light, it was use to about 8hrs. I also replanted it to a bigger pot, the soil had not been changed in a very long time and it needed more room. It also shares the pot with a large Jade plant and 1 small succulent. Basically, I just noticed today there looks like there could be mold in the soil near the Christmas cactus and Jade. The Christmas cactus stem looks horrible not healthy at all, but it is growing new parts of the plant, slowly, although it did not bloom at all this year. I'm looking for help to save this cactus. Any opinions or knowledge would be greatly appreciated. This is the only window I have that gets any light so moving it isn't an option, the pot is about 2.5ft tall there's rocks at the bottom and the soil is for cactus its about 6minths old now. I'm not sure if I've watered too much or not enough, I water it maybe 1 or 2x a week but not much water and it's always close to the stem, I also spray it 1 or 2x a week with misted water.