Look around TIREDTHYROID.COM . Some good basic info. It is not uncommon to have someone that is hypothyroid be missed and get pushed onto antidepressants, when all that was needed was to get their thyroid ranges in the optimal levels.
A WORLD of difference being WITHIN RANGE and being OPTIMAL. I do not think that is taught in med school. That site will also list the basic labs, both thyroid, iron, etc. that SHOULD be ran to get a clear picture.
There are few other great sites but this one is easy to navigate through and provides a wealth of basic info as a starting point.