The presence of webbing suggests spider mites. For more information on spider mites and a course of treatment, please visit the following links:
Based on your description, I also wonder if perhaps your camellia may be suffering from petal blight as well which is a fungal disease that occurs in spring caused by an abundance of moisture. The bud drop would also be explained by an abundance of moisture.
For more information on petal blight and bud drop and a course of treatment, please visit the following link: