Its not worms, its flagellates, they are not the same, flagellates are a much much smaller organism. You may be dealing with worms as well but in general that does not take precedence. Sounds like you've learned a lot of the necessary lessons. One thing ill say is that you should have two instincts when you have a problem in a tank. The first, test your water parameters (you really need to actually do this). The second, change lots of water and often, discus need a regular water change schedule which it sounds like you've already learned.
So first test your water parameters and rule out water quality as your issue. Second I need more info on exactly what you treated with, hexamita is a flagellate infestation, referring to a specific kind of flagellate. There's no liquid that i've ever used to treat hex or spiro so I just don't know what your referring to. Normal treatment would be metronidazole treated daily at 500 Mg/ 10 gallons, with as large a water change as possible being done before each dose.