don't panic. to start search on web is a good start, as we all have learned that endo sometimes are not giving us the best solution. try a new doc and before you go, make a list of the questions you want to ask. i am still on my way to find the best solution, such as what meds, what dose, what other test i should suggest to my doc(yeah, you shall act as your own doc)... i assume you meant anti-body, when you said negative? if so, you definitely need a thyroid hormone. it's just a matter of figuring out which one works for you and at what dose. it will take a while for that to stabilized i believe, and we are on the same journey with you.
Do you know what your last TSH reading was? Have they suggested doing an ultraound on you thyroid? What dosage of thyroid meds were you on? It would be helpful if you could tell us your results from your last labs.