Have your hormone levels checked. I did in January and discovered I was suffering from adrenal fatigue. Very low DHEA and very low cortisol. I started taking DHEA and cut out the stimulants, it took me 4-5 months to feel somewhat normal. Last month I went to the doctor and the DHEA and Test is even lower. The DHEA has restored my energy, but I'm not 100%. I see the endo in 3 weeks. I've never cycled.
I'm not suggesting you take DHEA, but get some blood work done just to see where you're at. fatique is also a sign of overtraining, so it could be that too.
BTW, I have not ingested caffine for 2 weeks. I was not supposed to anyway, but the DHEA was doing its job. I feel even better being off the stimulants, but it took of few fogger brain days to adjust.