Can you please send some photos? That will help more accurately diagnose what is happening. Thank you!

This definitely could be botrytis but there are some lookalike problems. One way to confirm is to look for the gray sporulation. If you're not seeing it on the plant, then clip some infected blossoms/berries. Place in a plastic bag with a moist paper towel. This will create a humidity chamber, and that will encourage the fungus to produce its characteristic spores (Look at the first photo here for an example). If you don't see spores after a few days then you may be dealing with a different issue like a bacteria or a different fungus. 

Here are some tips to help your plants thrive next year if this is Botrytis:

• Annually prune to remove infected twigs and to open canopy for good air circulation.
• Space plants for good air circulation and quick drying.
• Adjust timing and/or frequency of overhead irrigation to keep aboveground portions of the plant dry. Use drip irrigation.
• Avoid late-season fertilization that stimulates growth susceptible to winter injury.
• Practice good weed control.

Let me know if you would like information on fungicide options. There is nothing to apply at this time in the season. This is a disease that you need to make preventative sprays for.