My IUD is a NIGHTMARE

So I got the Mirena IUD inserted in June, at about 3 months postpartum. I literally have had my period for 2 months now. AND I feel like a hormonal mess. I cried over a fricken rhubarb plant at my grandma’s house the other day. I had to take a pregnancy test because I was soooo sure I could be knocked up again (it was negative and I did get a blood test the day before insertion). I am restless at night and can’t sleep, lacking motivation during the day, an absolute hormonal mess... just got hot flashes tonight.. like are there some crazy 6 months postpartum hormone adjustments I’m unaware of!? Or is this IUD just completely not working for me..