Recurrence with Tall Cell Features

I apologize in advance for the length of this post and truly hope everyone is doing well and staying as positive as you can.

I'm a 30 year old female, diagnosed with papillary thyroid cancer at the age of 29 last May. TT in June of 2016. 4.1 cm primary tumor, secondary tumor was .5 cm. Surgical margin was negative, one node tested positive but it was stuck to the thyroid so they kind of just took it out by accident. It was classified as "usual, conventional"and there was ETE. Staging was pT 3 N 1a M x (they didn't take out/test any nodes except the "accidental" one).

I then had 150 mci of RAI in October 2016, uptake was shown in the neck only, and the scan a week later showed successful remnant ablation from what I can remember (I still am waiting to get all of my Medical records sent to me). There was a huge spike in Tg (.4 to 24) after being stimulated for the WBS (TSH of over 300) and I have Tg antibodies. Since then blood work has shown a downwards trend in the antibodies which were originally over 1000 to now somewhere in the 400s and my Tg has dropped back down to .4 as it was after my surgery/pre stimulation. (I am however waiting on the results of my initial Mass Spectometry Test).

Here's where the new panic and dilemma arise.

I had my first follow up ultrasound January 2017. It came back with some suspicious nodes and a 1.3 cm nodule in the thyroid bed. Went for a core and fine needle biopsy a couple weeks ago and the results are a real kick in the ribs. Turns out I now have "recurrent papillary thyroid carcinoma with Tall Cell Features" .

I will be getting a left neck dissection to remove chains of nodes and get this nodule out. Of course now my terror lies in the fact that all of a sudden there is talk of Tall Cell features (I don't understand if this was missed on my original TT path report, or if all of a sudden I'm starting to de-differentiate). Also, my biggest fear of being non-avid seems to be possibly coming to fruition. I don't understand if this was a nodule that was missed in the original surgery, if it just grew back out of nowhere despite a pretty hefty dose of RAI, which to me suggests non-avidity. I realize the nodes sometimes don't take up the RAI as readily but this nodule isn't a node. My irrational mind is worried sick thinking that maybe this new nodule has anaplastic parts situated within it that the core needle or fine needle may have missed or maybe the lymph nodes do since they weren't even biopsied due to their small size. I'm feeling a bit of fullness when I swallow but I can't tell if that's because I'm letting my nerves get the best of me or I'm still healing from the 7 needles I got stuck with on Valentines Day. 

I'm currently shopping for a new surgeon and scheduled for an MRI and a couple consultations, but in the mean time I feel very scared that my pathology isn't as "garden variety" as I was first told it was. I'm diving down the dark rabbit hole of reading about de-differentiation into more sinister types of thyroid cancer. I guess what I'm wondering is is there any way I was misdiagnosed from the beginning? I know I should be dealing with the up coming surgery, but I feel as if I would have pushed harder for a neck dissection right off the bat if I knew I'd be dealing with a potentially non-avid more aggressive type of cancer. To me this seems to be growing or re-growing faster than I'd like seeing as I'm only 9 months out of my first surgery, and I feel so panicked it's been hard to calm down. I will also push for BRAF testing and more answers as I try to establish care elsewhere, but I'm meeting with my soon to be former surgeon tomorrow morning to tie up some loose ends and ask more questions and I was hoping for any insight.

My sincere thanks to anyone who takes the time to respond and offer support and educate me in the navigation of this "easy cancer". Thank you all ENDLESSLY in advance for any responses.