Hey alliejokerr,
Depression is associated with hypothyroidism, but there are nutritional treatments that can help with this. It has been found that people with hypothyroidism and depression commonly are low in B vitamins, especially B12 and folic acid. I would suggest you call a nutritionist and have an amino acids test done. This will show if your body is low in the vitamins and amino acids that help prevent depression.
For example, Tyrosine is an amino acid that acts as a mood elevator and aids in the function of the thyroid and adrenal glands. Tyrosine attaches to iodine atoms to form active thyroid hormones, and a lack of adequate Tyrosine can be a cause of depression associated with hypothyroidism.
The tests are important for finding specific deficiencies but if you like, you could try eating more bananas, avocados, almonds and other foods with a good amount of Tyrosine in them and see if you feel any better. ONE WARNING- if you start taking a prescription drug for depression, ask your doctor about avoiding Tyrosine supplements. The combination may lead to a sudden rise in blood pressure.
My son is taking a small amount of Levothyroxine, but also Hydrocortisone for adrenal insufficiency so I don't know how much of his depression was associated with his hypothyroidism. However, the tests his nutritionist did were more helpful than anything else for explaining what was really going on in his body, and what we could do to correct his imbalances. I strongly recommend these tests for getting to the bottom of both physical and emotional problems.
Good luck to you.