Mirena causing mood swings?!

Hannah
I recently got fitted with a Mirena cool (6 weeks ago) and ever since I've had strange bouts of depression and crying.  I was diagnosed with depression and anxiety over 4 years ago and have been on SSRI's for 3 years and even then I wasn't much of a cryer but last night, for example, I was lying next to my boyfriend and all I could think was 'he doesn't love me' which is totally untrue and unfounded.  I was sobbing for over an hour.  This isn't the first crying spell I've had since getting the IUD and I'm wondering if it could be connected or if I'm just going crazy? Anyone had any similar experiences?