I have a lot of these symptoms too. Memory problems, brain fog, lethargy, sleep problems, heart palpitations, headaches, dizziness, nausea, dry skin, etc. I could not find a doctor for a long time. I finally found one that specializes in thyroid and adrenal fatigue. He treats my symptoms rather than my blood work. According to my blood work I am in the "normal" range, so most other docs just say its in my head or I need better diet and exercise. I hope you can find a good doc in your area, because it absolutely sounds like hypothyroidism and adrenal fatigue.
I have the weird vision disturbances, too. Look up "visual migraines". It is basically a migraine headache that causes lots of floaters or TV static sparkles or like fireworks... It's hard to explain. It can occur with or without headache pain. I thought for sure I was going blind until I found out what it was! Mine are related to my adrenal fatigue, not a separate migraine issue.
I am also very sensitive to changes in weather, humidity, and light. I take more thyroid medications in the fall and winter, and decrease my dosage in the spring and summer. My doc says he has several other low thyroid patients that report the same thing.
When I am stressed or my body is out of balance, my body rejects some foods. Its like I develop a food sensitivity - usually gluten or processed foods. But, I can travel to a different place and eat those foods again. Its because the environment is less stressful to my body somehow, so I am able to eat these foods again without throwing up or having intestinal distress. For example, I was intolerant to gluten for 4 months. Then I flew to Europe and ate breads with no problem. Then, I flew to New York for an assignment and the gluten intolerance came back. I thought maybe it was because of the ingredients or something, but as I found a good balance of thyroid treatments, the intolerance disappeared all together. I can't really explain it, but it sounds very similar to what you feel as well.
Its like, when my body is too tired, it stops functioning or cuts corners in whatever area it can to conserve energy. My body will refuse to digest certain foods, become unable to tolerate humidity or cold weather, stop caring for skin cells, etc. Whatever shortcut it can take because the energy is just not there.
Good luck, and let me know if anything works for you because I am still not at 100%!