Regarding the possible effect of high fever on TSH level, I cannot find a lot of info about that: however, the little that I did find does not confirm that possibility.
Do you have any test data for the biologically active thyroid hormones, Free T4 and Free T#? TSH is a pituitary hormone that id affected by numerous variables, to the extent that it is effective in diagnosing only overt primary hypothyroidism. S it is best to always test for Free T4 and Free T3. In addition, signs/symptoms should be the main concern. A individual symptom can be non-specific, but having numerous symptoms typical of hypothyroidism is a strong indicator.
So please review the following typical hypo symptoms used by Mayo Clinic and tell us which ones you have, if any, besides depression.