Welcome to the forums. Sorry to hear about your problems.
Short answer:
I would immediately do a 25-50% water change, put some fresh carbon in the filter, and raise the temperature in the tank to 82 degrees.
Long answer:
The parasite that causes ich can't reproduce in 82 degree water, so the easiest cure (though it takes longer) is to just raise the temp. You want to do this slowly, only a couple degrees a day, until you hit the target temperature.
You also want to remove the meds/salt. The salt will take numerous water changes to remove. The meds can easily be removed with fresh
activated carbon.