IVF and possible sub-clinical thyroid issues (Hashimoto's)?

I haven't discussed my blood test with my doctor yet - but! I could use some support & advice before he has a chance to get back to me.

We've had a very difficult IVF process - so far spanning 6 years, two chemical pregnancies and two anembryonic pregnancies (one with donor sperm and one with husband's). We finally decided to move on to donor eggs, as blast rates weren't good and neither were our pregnancy outcomes (also I'm turning 40 this year), and we were so, so lucky to get two beautiful 4AA blasts that are currently waiting for us.

The issue is that prior to FET with donor eggs, my clinic ordered a blood test that no one's ever ordered before -TPO. Which was 6478 - massively higher than normal (60 or under). My TSH is normal at 1,5. Googling tells me that this means I am in very high risk of developing Hashimoto's, but that I haven't yet, as TSH is still normal - and I have prior measurements of my TSH-levels that show it within normal range since 2013.

All well and good, as this should be manageable with frequent blood tests and possibly medication during IVF and pregnancy. However - googling also tells me that TSH often is badly affected by estrogen, and knowing that estrogen rises significantly during IVF stims, this could possibly have led to increased inflammation and worsened egg quality. Maybe, if we'd known to keep and eye on this, we could have managed this during our 6 (!) years of treatment, maybe getting a better result? We are now looking at having children that are not 100% our genetically, and while I would love them unconditionally, I am so, so upset that we haven't even been able to try and see if fluctuating TSH-levels could be an issue in my IVF process.

I'm trying to not get too upset, but I'm still spiralling, and could use some hand-holding, advice and experiences.