Certified GKH Gardening Expert
Unfortunately, your photos did not come through. I am unable to address the situation. It could be infection from infestation, but it can be overwatering damage, in compensation for dry conditions, as well.
In the meantime, I would recommend a fungicide, and to keep a close eye on soil moisture. You want the soil to dry out, thoroughly, down to about 2 inches between waterings. This important soil layer contains the microbes that will protect your plant, and they cannot survive without oxygen like some of the more detrimental microbes can.