Very worried as ive been diagnosed with an overactive thyroid. My thyroid has been u der and made stable with thyroxine but it's now overactive and the dose of thyroxine was changed and it's still overactive so they have changed it again and in 6 weeks I will have another blood test to see what's what. I. So worried as this can lead to heart failure. I am having palpitations and lkst weight and have fatigue. Ive never been so worried I can't eat or sleep due to the worry.