Whilst the betta had the fin rot before adding medication, Im in agreement with others that using too many different meds, using several at the same time have probably caused more harm than good. Unless the case of finrot is severe then usually good regular water changes can help immensely, clean water can do wonders for repairing fins, only as a last resort would I use medication.
When you have used one medication, you should perform a 30% (or larger) water change, then add carbon to your filter to remove any traces of the medication before starting with another, too many different chemicals all at once will damage the fish whether it be in the short term during the treatment or leave a sustained weakness to their immune system in the long run. Understandably you were very concerned about your fish, anyone would be, its unfortunate that many different sites/forums give varying advice on different medications, those anwering do not always know the full story/history of the fish and the meds already used and in our attempts to get our fish better, we rush to use anything and everything we can find in a hope of a cure, your not the 1st to do this and its admirable how much time (and money) you obviously spent trying to make him feel better.
Suggestions of euthanazia were given as sometimes its the only option after trying all you can, your fish is worse and obviously struggling, its not meant as a lighthearted 'oh well time to end it' comment, its a last resort and unfortunately is has to be done in this hobby for the sake of the fish. Nobody here would even mention it unless they thought it was the best option.
The reference of the toilet, was in no way meant to cause offensive to you, its a regular question that is asked when trying to establish a form of diagnosis for the fish, often how they are 'pooing' is a good indication of their problem, is the fish poo normal in colour, consistancy etc.
If the medication you are now using appears to be working well, then by all means continue to medicate, if it stops working or the betta stops eating again, the fin rot gets worse, then I would advise you stop the medication and DO NOT use anything else. Your best course of action, would be to increase aeration into the tank, you can do this via an airstone or increasing the flow of the filter outlet (preferably angling this against the side of the tank as bettas do not like strong current) and perform daily 20% water changes to remove the meds, keep the water quality tip top and only try to feed once every few days, fish like us, when they dont feel well do not want to eat, if you continue to keep putting food in that is uneaten it will only dirty the water quality.
The people here have tried their best to advise you in the best way they know how and their advice is invaluable, nothing that was posted was meant to upset you in any way and I hope that the betta recovers well and lives a long healthy life. Good luck, let us know how he is doing and if you need any more help, people here are happy to give up their time to help you.
