I have been treated for hypothyroidism for 6 years. When my TSH gets high I usually experience weight gain, the mental fog, and extreme fatigue. It took about a month to start feeling better although it takes about 3-4 months to feel the total effect. The weight gain does not go away and I have to work hard to maintain weight. You are lucky not to have gained weight. I always feel better when my TSH is 0.5-1. My endocrinologist likes to see TSH levels of 1-2 when TTC and pregnant. Hope this was helpful.