Vicki do not panic. I use a systemic with a core ingredient called carbendazim and Hexaconazole. I do not know the brand names for the same chemicals in the US. You can look at Physan, I understand is the systemic of choice in the US. First of all, I would just remove the top layer of coco nut husk chips, they retain too much moisture and dry out slowly, make sure that the pseudobulb bases stay clear of the media. Repotting at this moment can be a problem if the root system is already stressed, I would recommend that you modify culture rather than repot. Water less sparingly, make sure that the foliage doesn't stay wet for long. Make sure it gets plenty of warm air around it. This together with the systemic should take care of the problem.