Interesting that Vitamin D should be mentioned. I've become very curious about that.

So, I took a week off and now I'm back to feeling like Wonder Woman. I am burning myself out a bit, and I probably need to rotate activities as was suggested.

However, I think my main problem was in my head -- I just wasn't allowing for the difference cold weather makes and I was getting negative about it. Once I got reassurance here, I was okay. We all know there's a mind/body connection, but this was a good chance to see how powerful that really is.