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.
The
amenorrhea 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.