Overactive thyroid glands?

I went to my doctor about losing hair and they sent me to go and do a blood test, I did the blood test and they told me to do another blood test in another 3 months because I was in the borderline for over-active thyroid glands. And I said okey now next month I am going to go and do my blood test but I am losing tooooooooo much hair, you can literally see my scalp I am sooo scared and worried because I want it to stop, I have another appointment what should I say and do????