What Causes Terrible Cramps After The Placement Of IUD?

hi im 15 years old and i started my period on tuesday morning, then on wednesday i had my mirena iud placed. my period stopped the next day on thursday. on friday i had unprotected sex. today (sunday) i am having terrible cramps and i cannot even sleep. i took equate menstrual relief and ibuprofen but it did nothing, i put a heating pad on my pelvis and had my boyfriend rub my tummy and let a fan blow on me but i just felt worse, so my mom gave me a vicodin and now i feel like i have a fever and feel extremely nauseous and very shaky. i feel like im dying from the inside. the pain has now spread to all over my abdomen