What is your daily work/sleep schedule like? Years ago, I went through this. I realized that I was simply burning the candle at both ends, and also not getting proper nutrition. I was in my 20's at the time, but still, 3-4 hrs. sleep daily wasn't cutting it and it caught up to me. After a week of good rest, 8+ hrs. sleep every night, I was back to my old ways again, lol.