I can't give you specific help to fix this, but, I can advise that you make an extra backup of your EFS. Copy it off of your phone if possible. If not, just copy it to a different partition on your phone, so you have more than 1 copy in more than 1 place.
If you attempt to return to stock with T-Mobile flashing tool all the data on your phone will be erased. So moving a copy of the EFS backup off your phone is the first thing you want to do. If you can use ADB with the phone you can get a copy of it off your phone.
After that, I'd wait for someone with specific knowledge of this problem to assist you in fixing it. Assuming the backup of your EFS file is good, you will be able to fix your phone.