I have never heard of such thing as confuse the fish when change the feeding routine. You need to cut back on feeding immediately. Feeding 2~3 times per day is definitely too much unless you are only feeding enough be finished within seconds. A single meal of no more than what they can finish within one minute is more than enough for the day. Some people only feed once every other day. Fish are cold blood animals. They do not need as much food as we do. More food only mean more stress on their digestive system as well as more ammonia produced for the aquarium which is toxic. I usually aim for 30 seconds unless there are bottom feeders such as corydoras catfish who will chew on sinking pellets and discs.