It sounds like there have been several changes in your health recently, including some concerning symptoms with the falls and low blood pressure. Certainly from that standpoint alone the best thing for you to do is see your physician right away for a thorough history and physical examination.
However, you also mention that you are having symptoms of a thyroid problem. There can be many different symptoms of abnormal thyroid hormone levels, including changes in your skin and hair, palpitations, changes in your energy level, difficulty sleeping, as well as some possible findings on physical exam (nodules in your thyroid itself, sluggish or overactive reflexes, changes with your eyes). If your physician is concerned that you may have a problem with your thyroid function, he or she can do a series of blood tests as well as consider an ultrasound
to evaluate the thyroid gland. In general, the tests that evaluate thyroid function are not affected by whether or not you have eaten before the blood tests.
If it is not clear exactly what is going on with your thyroid--or if there are other associated changes in your health, such as the falls and low blood pressure you describe--you should definitely continue a thorough medical evaluation. There are many reasons why someone can have problems with the thyroid, but the good news is that there are very good treatment options once you and your physician finish the evaluation. Your primary care physician
may also want to send you to an endocrine specialist. Good luck.