I'd take this up with your pdoc.
Adjustment can take time, I never found it to cause fatique, when I was on it. My oldest brother has been on it fo 30+ years and isn't fatigued by it,even works with machinery during the day.
Have you had any labwork lately for thyroid function?
If not you may want to do so, hypothyroidism can cause fatigue,depression,inability to lose weight,hair loss, and a whole bunch of other unpleasantries.
Your fatigue just may be temporary, and not from your meds. it can come from manic episode's passing, the high energy ebbing.
It's best to just check with your pdoc, just to rule out what is or isn't the cause. Knowing what it is may help reduce unecessary anxiety that can come from "wondering what is causing this".
I can drive myself batty when I have something I can't explain, I start worrying what is it or what is it not.
You may need a different med. or a combo, or just a dose adjustment, don't get discouraged, there is treatment for this, and a better selection of meds than many years ago.
Lots of luck with this, let us know how you make out.