Really sorry to read about all your problems. Others will probably be horrified with this suggestion but if it was me at this stage I would probably take my fish out of the tank, completely strip it, rinse it with janola, rinse it out really well again (several times), do the same with the filters, heaters and everything else, refill it with water about the same temp, add water ager and put the fish only back in. No stones, plants, just a bare bottom tank and then hope like hell that it works. No, the tank won't have cycled or anything else but if you can't do the meds theres not a lot else you can do!
I know how you feel, lost a tank full (40-50) jarred male fighters last year to a bacterial infection, tried for weeks to save them to no avail.