Sorry it took so long to get back, but I did some research and also consulted with my husband before coming back again.
I brought you some options, but they will take time, patience, and some expense.
For starters, I researched that medication you have been using.
I found the company website, and it is posted that in saltwater aquaria, it is safe for fish only tanks. If your inverts have survived, I would call this a lucky break. The 2nd thing I discovered is that the medication you need is for parasite treatment of the ick, but this is a bacterial treatment... so not going to help ick at all.
One thing you can do that will help (alongside of the meds I am about to suggest) is a UV sterilizer. That would also help protect you from future outbreaks. Especially in saltwater, it's a good investment, so one you may really want to consider if reef keeping is something you wish to do.
Are the fish still eating? If they are, even while in the main tank, you can offer them pellet food soaked in metronidazole or quinine. (Use one or the other, not both). This will help treat for anything internal that may be causing them issues, it's an antibiotic. In the main tank you can't really medicate for ick because of the inverts, as I mentioned previously... but if you are willing to set up the quarantine tank, copper would be the best thing to treat the fish. The fish would need to remain in the quarantine tank for 4 wks, while the ick dies out in the main tank. If they are returned any sooner, they will be reinfected almost immediately.
I can go into more detail, but at this point, I have not heard back from you so I don't know if you wish to invest what it's going to take to get this tank well?? I will watch this thread, and if you choose to do so, can then help coach you through the steps to get stable and healthy again.
Be forewarned, due to the size of your tank, the tang will need to find a new home. The tank was horribly overloaded with fish before the deaths... with what remains, if the tang is removed, the rest could stay and you would have a full tank. Animals beyond that would be corals, but no more fish due to waste, space, and oxygen levels, among other things. So, what do you say? Shall we try to save what's left?
(Oh, and minus the tang, a quarantine tank could be downsized to about a 40 breeder, which would make things a lot less expensive; and a good filter would be a sponge filter, which also isn't real expensive.
I'm all about saving money wherever I can, so if that helps to sway your decision...
I would also suggest checking your Calcium levels (should be about 400) and specific gravity/salinity (should be 1.023). That also will greatly affect the fish and inverts.
I hope this was of some help...