What Causes Nausea And Pinching Sensation While Having IUD?

i had a iud placed 2 years ago. i have experienced alot of pinching over the last couple months, so i decided to check if i could feel the string. i couldn't feel the end of it but it felt as if it might of looped up into me. i have also felt nauseous for about 3 months i have also lost about 20 lbs in the last 6 months, and no matter how much sleep i get i can barely get out of bed, i am so exhausted