The ich you are seeing on your fish is @ the end stage of its life. What you need to do is treat your tank. This parasite is swimming all over your tank (when you see it on your fish, like a tick on a dog, it has about 15 days left before it drops off & starts dividing/ multiplying). This parasite can only take certain water conditions.
1) Ich can?t survive in temperatures over 85 degrees. Not saying to pump up the heat, but if you do, take it slowly so the fish can adapt
2) Increase salt level in tank: NOTE some fish can?t take the added salt. Do your homework
3) If outbreak is extremely bad, do frequent/ large water change (30-40%). I personally am not a believer in this point but I have never had to deal w/ watching my fish die from ich
4) Use medication on fish. You can choose to do this during freshwater dips w/ some copper. Rinse fish off w/ your tank water before reading to tank. Also keep in mind your fish are very week now & might not survive the dips. Most likely your fish are suffering from this because they are not in the best condition to start with.
Please remember that ich is pretty common in tanks. In the future quarantine all new livestock & never add foreign water to your tank (water fish came in). Even w/ trusted dealers or great looking fish. Most FS use a plumbing system that?s all connected, so if there?s one sick fish in the store all the fish can be potentially sick. Hope this helps