Thyroid antibodies TG Ab at 154.3 IU/mL. How serious is it?

It means your body's immune system is forming antibodies against your thyroid. It's a bit odd to have anxiety and depression at the same time if it's due to thyroid. Are you sure you didn't start out with anxiety and now it's more depression as time goes on? The reason I ask is that anti-thyroglobulin (TG) antibodies is a sign of autoimmune Hashimoto's Thyroiditis.