Bad luck Nurj...but also good news it was caught so soon.
My consultant advocated I131 total destruction of the thyroid as a non-invasive way to remove all potential hinderances to recovery - might be useful to get a referral to my chap (NHS) if you need it - let me know if you need the details.
Did you have regular samples taken for pathology post-surgery then?
If it helps, I131 treatment was not only totally painless, but extremely quick. You get a session with the nuclear physicist who gives you the radio-nuclear pill, and basically have a chat for as long as you want before you are comfortable enough to take the pill. (I did not realise this, and thought it strange that he was prepared to answer all my off-point questions about nuclear treatment and radio-nucleides...!) Only issue is staying away /sleeping away from partner / children for 10 days or so, and using different bathroom facilities, as the wastes comes out in sweat, urine etc.