Take it as a positive sign of future improvement! I too experience the same thing, (Tinnitus being much quieter when I wake up in the morning.) Sometimes I just lie there for awhile reveling in the moment, knowing that as soon as I get up and begin making/hearing the normal morning sounds my Tinnitus will begin to ramp up. My T is greatly affected by sound waves entering my one good ear and doing something like just running the sink water in the morning will set it off. (Major hyperacusis)
The "fullness" on the right side of my head (my deaf ear) has also begun to get much less noticeable, although it still is a bit up and down. But definitely an improvement of where it was when this whole thing began 5 months ago.
There are now more and more environments where I used to need an ear plug in my good ear where I now can tolerate going without. Hopefully I will add to that. I still cannot tolerate being inside a noisy cafe type environment without putting an ear plug in my good ear. At least we are headed in the right direction. It's such a relief sometimes to have that feeling that "yes, I can live with this".