Any Post-Nursing mom's here?

Not to give out too much info, but.....My daughter decided last Saturday that she didn't need to nurse any more...yeah for us! Unfortunately, it is wreaking HAVOC on my body! I am getting migraines every day, I have NO energy, and I have serious engorgement. I struggled through all my work-outs this week, actually burning more calories than usual, and ate the same regimine. But, I only lost 1/2 pound! I am trying to figure out if it is my body trying to plateau, or whether it is related to stopping the nursing of my daughter. Anybody who has been through this stage of life, I would really appreciate your input! Thanks-Sunny