Hi, Welcome to Health care magic forum. Mirena
is a progesteron steaded I.U.D. and there would have been some change in the composition, which caused the changes.
The other causes may be anemia
, infection, or changes in the harmone levels.
may be the cause of the belching
stomach, sore breasts etc.
I advise you to consult a gynecologist for diagnosis and treatment.
Take more of green leafy vegetables, pulses, sprouts, and proteine rich foods.
Wishing for a best health. Thank you.