Yes, your TSH is very high, but not the highest we've seen here. It will start to reduce and your FT4 will start to increase as the Levo starts to take effect.
The aim of a treated hypo patient generally is for TSH to be 1 or below or wherever it is needed for FT4 and FT3 to be in the upper part of their respective reference ranges if that is where you feel well.
I hope your GP has started you on a loading dose of D3 and not a maintenance dose. They're very fond of prescribing just 800iu which isn't even a winter maintenance dose for someone with a reasonable level.
NICE treatment summary for Vit D Deficiency:
"For the treatment of vitamin D deficiency, the recommended treatment is based on fixed loading doses of vitamin D (up to a total of about 300,000 international units [IU]) given either as weekly or daily split doses, followed by lifelong maintenance treatment of about 800 IU a day. Higher doses of up to 2000 IU a day, occasionally up to 4000 IU a day, may be used for certain groups of people, for example those with malabsorption disorders.
Several treatment regimens are available, including 50,000 IU once a week for 6 weeks (300,000 IU in total), 20,000 IU twice a week for 7 weeks (280,000 IU in total), or 4000 IU daily for 10 weeks (280,000 IU in total)."
Each Health Authority has their own guidelines but they won't differ much from that.
When taking D3 there are important cofactors needed, which your GP won't have told you about because they're not taught nutrition.
D3 aids absorption of calcium from food and K2-MK7 directs the calcium to bones and teeth where it is needed and away from arteries and soft tissues where it can be deposited and cause problems.
D3 and K2 are fat soluble so should be taken with the fattiest meal of the day, D3 four hours away from thyroid meds.
Magnesium comes in different forms, check here to see which would suit you best and as it's calming it's best taken in the evening, four hours away from thyroid meds.