ok, many problems here, first problem and the biggest problem you have, the tank is too small for it, two goldfish alone require 30 gallons or more, i can go on forever on why they need a bigger tank but that will take a couple of pages.
Ok all your other problems are connected to the fact you cannot have goldfish in a bowl. Also im looking for water parameters not what type of water that you use. But this wont matter as i know exactly what is wrong without you telling me the parameters
The goldfish is suffering from a highly toxic ammonia poisoning. In case you didnt know ammonia is created after a fish poops as the poop decays. Ammonia will burn the gills like acid litterally suffocating the goldfish, the goldfish is in dire need of oxygen so it "gobbles" water from the top of the bowl which carries the most oxygen. No matter what you do you cannot fix this problem in this bowl simply because it is too small. It will die if you dont act fast.
Now what you do: get the goldfishes a bigger tank, a tank bigger than 30 gallons for them with filtration enough to filter a 60 gallon, if possible you can give them away to someone who has a tank that can house them or a pond as a pond will be even better. Thats all you need to do, simple as that, as you are getting the goldfish tank ready, do daily 50% water changes this will buy you a tiny bit more time. Once set up immediatly move the goldfish into the big tank, if you are able to keep the ammonia down in the 30 gallon using water changes (no chemicals) the goldfish will heal by itself. Please act fast, the goldfish wont last long in a bowl. I wish you the best of luck.
Do not blame yourself for this, it is the companies that make and sell bowls fault, they shouldnt advertise bowls for goldfish, the only fish that can fit in a small bowl is a betta (there might be more but the betta is the most common) Its sad to know that the second most popular bowl fish is actually one of the worse for a bowl.
Please also understand i am here to help, whatever questions you have ask them, however stupid they sound, this forum will help you out great. I wish you the best of luck with your goldfish, i hope it will be alright.