I'm with starting over. I think it will be the best idea. Take out the rocks and scrub the tank interior. Maybe theres something in the tank that poisoned everything, you wont know unless you clean it well.
have you tested your water for copper btw? Some fish stores run copper with their fish and if any of the lfs
water got into your tank that would have been very bad.
It's just an odd thing that I thought of. One of my LFs
' run copper and warned me explicitly not to get any water in my display tank.
Hang in there, you have a great setup and it would suck to not use it. You know you can do it. I bet your tank looks even better this time around.