How long has your tank been set up? You still have detectable ammonia. I would not recommend trying again for several months.
From the picture on the first page, the bta was not the healthiest to begin with (appears slightly bleached), but far from the worst. After you have had your water parameters stable for months, you could probably try it again; however, I would recommend searching for an aquacultured bta and/or starting out with a healthy one. I would also say when first introduced, do your best to never touch it/ move it around, just let it wander, while keeping track of it and inspecting its condition. An open rockwork aquascape helps prevent a scenario of it going into the back of the tank or an area that is out of sight and having to move rocks to locate it. Stability is key.