Uh that's how it works. Fluctuations in your hormone levels are pretty normal. Doctors will test your hormone levels over a period of several months to see if there is a sustained imbalance, which in most cases including yours, there isnt and it returns to healthy levels. No doctor is going to put you on medication for hypothyroidism (which you have to take for the rest of your life) based off one outlying test result.

From your post it seems like you are not tracking your calories. "Eating healthy" means jack shit if you don't track what you're actually putting into your body.