Lithium and sleep issues

[fer1 0]

Hi there - I am currently on Lithium and Remeron.

Feel it is the Lithium making me feel dead , lacking alertness. Emotionless.

I want to get off it. However, I am sleeping quite well (although awaking very groggy)

Is it the Lithium that is getting me to sleep or is it the Remeron?

I so , so wanna lose the Lithium so I can begin to feel human again. If it is the Remeron making me sleep i'd be 

off the Lithium as soon as possible (slowly tapering)

PS im am not Bipolar.