dried daphnia, flake food(both of which i now soak),
I owuld assume this came about as a recommendation to keep the flakes from ballooning in the animal's intestines??? Goldfish are notorious for floating upside down and sideways because of ingesting dry food. FYI, goldfish do not have stomachs. Anyway...
I think you have too much meat protein in the diet. Goldfish should be fed a goldfish flake food. If you are feeding any other type of flake food, like for tropical fish, it should be changed. I would suggest to cut bloodworms out of the diet altogether and any other meaty foods and stick with the daphnia as a meat protein source. Veggie protein is more important. Mix a good veggie flake in with the goldfish flake and make that the staple diet. I like HBH veggie flakes. Great ingredients. It's like feeding your fish a healthy salad
Fantail goldfish are slow and do not need a lot of food. No more than what the animal can eat in a two minute time period per day divided into two or more feeds. This should be offered every other day.
Here is some info on swim bladder disease. This is still a possibility, so read up on it and perhaps do a preventative type treatment just in case. Use something mild just in case it's not related to swim bladder disease like some Melafix for the time being until more is known.
http://www.netpets.com/fish/reference/freshref/swimbldr.html
It's always in good practice to test the water for any imbalances with the bio whenever you think something may be wrong. Ammonia, nitrite, nitrate and pH should be tested and please post results.
How long has the tank been going with fish in it?
What type of filter?
How long have you had the fish that's in the QT?
Has the fish pooped at all within the past few days? If so, what color is it?