Mirena Complications

I've had Mirena for about a year now, at first I didnt really have any problems just the occasional cramping. But around the end of December beginning of January I started having some issues such as:
- Severe Cramping
- Severe Depression and mood swings
- Migraines that last weeks on end
- Lower back and abdominal pain
- Pains throughout my legs and sometimes my chest.
- Discharge with an odd texture and odor.

Back in March I had some pretty severe cramping and heavy bleeding which caused me to leave work early and seek medical attention. This lasted roughly 3 days and I could barely move at all. I lost my appetite and didn't want to do anything because everytime I moved I was in excruciating pain from the midsection all the way down to my feet. When I was at the hospital they did an ultrasound and said everything was where it should be and there was no problem that they could see.
About 2 months ago I couldn't find my strings, and haven't been able to, I thought maybe my body expelled it but I don't think thats it, I was told if that happened I would get my cycle and I haven't had any bleeding since March.
I have an appointment tomorrow morning to have it checked and hopefully removed.
Does anyone have any idea what could be causing all the pain and discomfort. I find it hard to have intercourse because everytime I do it hurts so bad. If anyone knows anything please help me out.