Apparently, I had mono.
I have no idea when I had mono. Or how I got it. But one of the tests results showed I did. The range for the results were 0-20 and I was over 200. I haven't gotten to talk to my doctor about it in detail, but I did stop by the office and make sure I was okay to work (especially since the office orders food from my job.) They said yeah and to make their next order extra tasty. They also said that this was likely the cause of my fatigue and there was little I could do about.
Just freaking peachy.
Lucky me, but at least I'm getting somewhere.