Q.Problem with holly
Hi. I wonder if you can help. My holly has started to shed its leaves which are yellow with black spots on them. I have fed it with fertilizer for azaleas etc in case it is iron chlorosis but it still seems to have some yellow leaves and dark spots.
Can you help as I do not want to lose the holly? I have attached some images. Any advice on how to save the holly would be appreciated.

Are the yellow edges of this plant's leaves a new occurrence, or has it always had this leaf coloration? I ask because the leaves look like variegated holly varieties that naturally have white or yellow leaf edges, for example in the following photos. So the yellow is probably normal.
The black spots, on the other hand, are likely a disease. These articles describe holly leaf spot diseases and what to do about them:
https://www.gardeningknowhow.com/ornamental/shrubs/holly/holly-problems-holly-leaf-spot-or-holly-tar-spot.htm
https://ag.umass.edu/fact-sheets/holly-leaf-spot
If leaves are falling off in patches, it could be this:
https://www.rhs.org.uk/advice/profile?PID=175