It sounds like you may have a fungal disease called botrytis HERE’S a link that discusses that. During a damp, humid season like the one we’re having, diseases are common. Don’t promote disease by spray watering your gardens. Use a watering wand to direct the water to the soil while keeping the leaves and flowers dry. Wet plants make it easy for diseases to take hold. MORE ON THAT HERE. Now that the disease has takn hold, you’ll need to spray with a fungicide like Bonide Fungonil.