485 medical evidence request--TB skin test result

I had a TB skin test positive reaction, but my X-ray was normal, when I submitted my medical exam for 485 last year. The doctor recommended me some prevention treatment, which will take 6-9 months. He said it is optional and up tp me. So I did not do it.

Now, the immigration officer requests evidence of completing the treatment and a new skin test result. Here is the original message:"Your I-693 notes that you had a reaction to the Tuberculin Skin Test and that you were recommended for treatment. As such, you must complete a new Tuberculin Skin Test to establish that you have completed treatment and that the condition is no longer active or contagious."

The doctor said as long as I start the treatment with him, he will write a letter for me to prove that I have started and it should not be a problem. However, I am sure I will still have reaction to the new skin test. I am very worried. Do you have any similar experience? Do you know anything that I can do? Thanks a lot!