I was like you. A year ago, I was tired as hell despite sleeping (well, not enough, but I've never slept 'enough'). A few people said sleep apnea but i was not overweight and didn't snore. I tried the test anyway, and it turns out I wasn't breathing. I used an oral appliance and a year later, it's gone and I feel better.

Also, without doing anything my triglycerides, LDL cholesterol and blood sugar which had gone way out of whack, went back to normal.

I started using my oral appliance on a Monday. That Friday I was so energetic I ran 12 miles in one go. I hardly ever run or even practice that much, but I was just so wired that I couldn't help it. It was an amazing feeling. I highly suggest sleep apnea treatment even if you don't think it sounds like you.