Yes, it will have to be done in Texas and the original court where the J&S was first filed.
At $11K, I think that the original attorney would be will to correct this, (especially since he admnitted fault in writing). You should definitely be talking to that attorney.
It is excellent that you have kept all paperwork, most folks don't. Based upon what you have explained, I do not believe it is insurmountable, but you are going to have to keep at it. Also, from an economic loss standpoint, you would also benefit from using another attorney, if the first one won't clear up his mistake.
All of the information above still applies, you're just gonna have to remain persistant.
I hope this helps. You don't need to hit accept again, (you'll be charged again if you do).