Not only was it a rest day, but it was also a snow day!
Besides that, I went to the doc to see what was going on with my lower back. To give some background into the whole thing, my back/butt area has been hurting me for the past two weeks, and I suspect it had something to do with some Deadlifts I did around that time.
After I explained my CrossFit-esque lifestyle, my doctor was quickly able to identify the problem. Apparently I had a slight tear in my hamstrings located near my sacrum. I asked how this could happen and he told me it was from not stretching.
We went over a few stretches and ways of getting back into the deadlift regimen again. Hopefully, after a few light weeks I can go back to lifting heavy.