Jenn you don't mention anything about your labs. What are they like especially Free T3 and Free t4 ?
It is important to keep the medication for hypothyroidism regulated. Usually we can do this within six months of establishing a diagnosis then recheck every 6-12 months depending on other medical issues.
Going back and forth like this means you are either getting a generic sometimes, not taking the dose consistently (either missing doses or taking it different times of day), OR changing diet or other medications -- these may not be the case. The other possibility is that the lab value is actually ok, but the doctor is making a change due to a rigid idea of what the TSH range should be...
do you have hypothyroid(underactive thyroid)? actually that is normal so that they csn properly treat the disease once you have a thryoid problem it will never go away i have hyperthyroidism and congestive heart failure i might die without medication so i have to constanly go in. it is benefical for you to contually go and get your screenings done. i am also a certified medical assistant