By the way, I just realized it's quite a bit more grim than blossoms shriveling. But that's how it started....

What has your weather been lately?
Tomatoes do not like wide temperature variation, too much soil moisture or too little soil moisture and will often drop blossoms if its too hot, too cold, too wet, or too dry.
Difficult to say but your tomatoes might be affected by Early Blight.

Your location is NC (North Carolina, I assume?). I found this on the NCSU extension website. I hope it helps.

Here is a link that might be useful: Tomato diseases

It has been raining a LOT the last week. A few sunny days on the schedule now. Hopefully it will perk them up. Thanks.