Hi I wrote a long mail about menstrual problems and recovery from Mirena to another poster. You didn't say your age, but if you're over 40, you may have palpitations etc due to peri menopause onset.
The palpitations I had were severe when I had the Mirena removed. I was breathless and my abdomen had swollen, I was depressed, low, anxious and lethargic, brain in a fog with sensitivity to light and migrane feeling. When I had it taken out, I did feel better, but the low mood persisted and lack of energy. My body was sort of in the habit of being inactive and feeling cra**y.
Fish oil supplements and actually eating fish 4 or 5 times a week helps. I would recommend exercise, follow someone like Zuzka Light on Youtube, she does intense workouts for 12 mins, so check it out with your doc first. Physically the results are amazing, but it sort of burns off the anxiety too. A long walk and deep breathing every day. Drink plenty of water, and don't go near alcohol, it doesn't help me anyway, makes palpitations worse. Try kelly Howell Meditations on Youtube, they are very uplifting and restful, 30 mins every day. Give yourself one day a week to really chill out and make sure you get enough sleep without music, light or disturbances. Don't overload yourself with commitments if you're feeling under pressure, it increases your general anxiety level.I found Kundalini yoga excellent, the chants and krias are designed to support and strengthen your endocrene and nervous system. Seeing a holistic health expert really helped me, I would recommend this. Make sure you are getting enough vitamins.
The superfood/supplement Maca helped me, it balances hormones especially in women coming up to or past menopause age. Love yourself, sleep, exercise and try laugh out loud every day, you will find things improve. Write down a list of what you'd like to do and work through it, do new things, fun things, quirky things, educational things, something different. It helps change the bad habit of thinking about your health which the Mirena listlessness, brainfog and illness caused. Trying new things gets your body acting and feeling more normal again. let your body heal itself with natural rememdies. I hope you feel better soon.