Do you nap ever? Your problem could very well be something more than that, but napping can take some of that edge off.
Effexor does also cause drowsiness, although you're at a low dosage level so it shouldn't affect you too much.
did you fined a solution or a reason ?
i have the same problem for many months :( it affect my study and makes me depressed ...
if you ever find something .. pls tell me
Also I have been feeling a little bit weaker and having less energy.
I guess just not feeling like myself.