I couldn't stay away from crochet for a WHOLE WEEK, so on Day 3 I went desperately in search of a cure. I found a very helpful thread on Ravelry about icing for short periods of time, frequently, and that has helped a ton! My wrist still clicks a bit, but it's hurting much less and no more numbness
Finally bought my background color for Mario and was able to finish the top row (14 squares) and most of the blue squares for Row 2 (7 squares) in the past few days. I already had the top of his hat done, so 3 more squares and I'll have two completed rows! I've decided to go a full row at a time instead of trying to do Mario first then the background -- all one color gets boring after a while!
Also, I'm definitely finding that weaving in ends as I go and sewing them together every 2-3 squares is helping in the long run. It keeps things a little more interesting, saves my wrist a bit, and helps me feel like something is "done."