Help with interpreting my results

Your TSH is too high - should be one or below when you are on thyroid hormone replacement - your FT3 is a bit low, and you aren't converting very well. Your vit D3, B12, and ferritin are all much too low, and that could be why you aren't converting very well.

For the B12, you need to take 5000 mcg sublingual methylcobalamin daily for a few months, then drop to a maintenance dose of 1000 mcg for the foreseeable future. With that, take a B complex to balance the Bs - because they all work together. Best to get on with methylfolate, because it's better absorbed than folic acid.

I hope someone else will come along and tell you what to take for vit D and ferritin, because they really do need supplementing urgently.

No point in testing magnesium, because it will always be in range, due to the way the body handles magnesium. But that doesn't mean you aren't deficient - most people are. So, most people just take about 350 mg daily - especially if you're taking vit D3, as it's a cofactor.

So, given all that, it's really not surprising you don't feel good!