it likely means that your thyroid gland is not functioning properly and is not producing enough thyroxine. The fact that your antibody titre is high also means you likely have Hashimotos thyroiditis which is where your own immune system attacks your thyroid gland and eventually shuts it down.
I would guess you have symptoms of feeling cold, putting on weight, very tired, brain fog etc etc
you need to be seen by an endocrinologist and be prescribed some form of thyroxine pills to take daily. I would also suggest you go online for some support to the thyroid chat rooms as treatment for thyroid conditions is patchy and often awful