Did you neutralize the acid via backing soda?
I don't know where you live, but where I am, I have found several Craigslist offers for totes and brutes, just to be able to give you the added initial volume.
I found out that the initial filling of the tank, was the hardest part so far. Just having to make that much sw at once, and then once it's done, you never have to make that much again.
Maybe you can check with your local club and see if someone has a brute or two you can use just till you have enough to cover the rock.
As far as your ammonia, have you been ghost feeding? Where is the ammonia coming from?