BG are good but feeling like I need more insulin.

Maybe it's just me but that feeling you get when you feel like you need more insulin, not because of high BG, but because your body feels low on fuel?? It's hard to explain but I've been feeling like shit lately, BG are good but for some reason I feel like I need more. I remember when I first started my pump, I had good BG but a lot of lows also as I was tweaking settings but man my energy was crazy!! Now I have none, always tired and just feel like crap. Not sure what's going on.