I Was Given Synthroid A Few Years Ago Then A

I was given Synthroid a few years ago then a thyroid ultrasound, then another TSH and the MD stopped the Synthroid. Again, I was given thyroid tests, started on Synthroid for 6 weeks and then another blood test. The result this time was 8.7 which is higher than when I started the Synthroid. Im confused about what I have since 8.7 is higher than before the Synthroid. And what would indicate stopping Syntrhoid after an ultrasound?