This is not likely cancer. I am not sure why you are being referred. Would consider taking a step back and consulting with an internal medicine doctor to review the history and evaluation. The thyroid seems normal and not likely the cause of symptoms. Pain with palpation of the lower neck is not uncommon.
Well, don't get too scared too quickly if you can help it. Doctor's are wrong and I am learning more and more that when it comes to thyroid stuff they just don't know. When I called kaiser about having lumps in my throat, they said that I sounded like I had cancer and kept asking me questions about family members with cancer or if I had previously had cancer. I was just like "WHAT?!?! OMG Nooo! I'm dying!" and then when I had strep for 4 months because they kept giving me the same strain of antibiotics when I told the doctor not to, they wanted to pull out my tonsils. . .then hypothyroidism was dx, then PCOS, now insulin resistance and high cortisol levels, testing for cushings-they still don't know what's wrong, the lumps are still there, and I finally found some doctors that know what they are talking about after 4 or 5 years.
Normal ranges are as follows: TSH .45-4.5, T4 Free .82-1.77, Cortisol- 6.2-19.4 (cortisol is highest in the morning and should be its lowest at night time that's only if you work a typical schedule) I don't know T3, sorry.
First off: medications and foods can affect blood test results, thyroid hormones specifically. Birth control pills among many.
2nd: Blood tests are not 100%. Just because it is normal one day does not mean that it won't be off on a different day. Bodies fluctuate and it might be worth doing a recheck.
3rd: I have seen multiple "thyroid" doctors and people who claim to be "endocrinologists"- I have been told everything from you have cancer, to take out the tonsils, to nothing's wrong with you, you need to see a therapist, you just need to lose weight and exercise, to you must be lactating. . .what?!. . .seriously, she did not believe me when I told her I wasn't lactating. You would think that I would notice if I had stuff oozing out of my nipples while I'm not pregnant. Ha!
My point being, that maybe the thyroid doctor you have just doesn't know what else to do for you since her guess of it being a thyroid problem appears to be wrong. Has anyone checked your white blood cell count? Have you researched and found any other medical conditions with those symptoms? That doesn't seem like much in the way of testing. Also, I'm assuming eating habits haven't changed, no new stresses, no new daily habits or exercising, no new medications, etc.
Either way, I think it helps to look at all of this as ruling out the possibilities. Who knows what is wrong. I mean, obviously something is wrong and you're not doing well for your body to be reacting that way. There is no question in my mind that you are sick and need some sort of treatment to get better. So, the real question is "What treatment do you need?" For example, I am on a combination of metformin and levoxyl. Metformin can be used to lose weight, help PCOS, potentially helps Hypothyroidism, as well. The primary purpose of metformin is to treat diabetes. So, we're looking at a bunch of conditions with the same treatment. Maybe there is some potential for looking into that. Sorry, I don't really have any concrete answers, but sometimes knowing you're not alone helps. Good luck.