Hi
You have a condition wherein raised antibodies ( TPO) is preventing your
thyroid gland to produce enough thyroxine hormone. Your thyroid gland is producing the hormone, but not enough to meet the body needs. Hence you need to replace the deficiency by taking thyronorm which is nothing but synthetically produced thyroxine hormone. As the antibodies will be in your system for the rest of your life, you will be needing to take some sort of replacement for ever. The amount you need might fluctuate though, hence you need to check
TSH levels on a regular basis to ensure it is with in normal range. If it is high you will need to increase your thyroxine dose and if it is low, you will need to reduce the dose .
Hope the information helps.