You can see the nutritional profile of prunes here: http://nutritiondata.self.com/facts/fruits-and-fruit-juices/2043/2
They have more free glucose than fructose, which will probably have been absorbed in your small intestine. Problems could arise from fructose malabsorption, which allows fructose “access” to the bowels where most of the bad guys are. If you have an overgrowth in your small intestine though, it’d probably cause issues whether you malabsorb it or not.
Do you get bloating or pain above the naval? Symptoms almost straight after eating? Acid reflux? These could be signs of small intestinal problems.
Anyway, it was just three prunes, which also had some good nutrients in them. Worrying about food is going to do more damage than 10g of sugar. Read up on what your body does during a stress response and you’ll see how it would please opportunistic yeast. Expecting symptoms sets you up for a nocebo effect too. There are physiological reasons for cravings as well as psychological ones, so listen to your body. Next time try eating something satiating when you feel cravings. Some avocado or oat bran or something. Don’t go hungry whatever the time and try to relax!