Is It Safe To Withdraw Synthroid With This TSH Test Level?

i have been diagnosed with hypothyroidism. initially my tsh levels were a 6 and my doc prescribed .25 mcg of synthroid. i take it everyday. i am also on 100mg of zoloft daily. which i also never miss. at a follow up my lvls were at a normal 2.8. i was instructed to continue the same dosage. i have just recently had another test to see if my tsh had regulated and stayed nprmal and it is a .09. i am now being sent back in for antibody testing and was told to discontiue the synthroid until my 6 week follow up. why is this happening. i should state im 5 7 at 255lb and a 40% bmi.