If you use copper medications in your DT all your inverts will be toast. This includes snails, starfish, and any corals, not to mention all the beneficial bacteria in your live rock. Personally, I wouldn't use copper anyway. It is very hard on most fish, especially those already compromised. Do a quick search for the tank transfer method (TTM)
First thing tomorrow, go get yourself a tank to use as a quarantine/hospital tank. All you really need in it are a powerhead and a heater. Depending on what fish you have (and they ALL must go in there) you can get by with a fairly small tank, or even 5g buckets. If you follow the TTM method, you can have your fish Ich free in a fairly short time. Your DT, on the other hand, MUST remain fishless (fallow) for a minimum of 72 days. There really is no way around that.
hth