Thyroid blood work: High TSH, high thyroid-stimulating antibodies, normal T3 and T4?

Though high TSH indicates an underactive thyroid, I have not gained any weight. In fact, I’ve lost 30lbs in the past 6 months. I am a little too tired. I also get depressed, anxious, and shaky. I have an endocrinologist appointment soon, so I guess I’ll find out, but can you tell me what this means?