I think it might have to do with not knowing what to do with my character. I just closed some obby gate that i found in the woods. and went back to the main city to think of something to do. I started to progress the story a bit more but I'm at a slow part. And I dont feel leik progressing in my thieves guild quests.
I just dont know what I want to do in the game. >.>
This game definitly does tend to start losing your intrest after awhile. I think it is something to do with some of the changes from Morrowind. Level scaling and such. Still a fun game just a bit more... Dificult to stay intrested.
My advice would be to go do something else. Play some Civilization IV and then come back to it in a few days. I'm taking a break myself now.