Congrats on the half, Tony!
I'm type 1, so my advice on bg control should be seen from that perspective, but here are my thoughts.
Carb-loading is something that has been shown to have only marginal benefit in elite athletes. For most of us, it is wasted effort and risks putting our metabolism out of whack.
It is less likely to help in a half marathon than a marathon.
Even for elites, there are different carb-loading plans, and some of them involve only what happens in the day or half day before the race.
DEA is right about going out too fast. It is very easy when you train yourself into good shape, then start running with all that excitement, to feel like it is too easy, you just have to go faster.
I also talk to a lot of people, especially training for marathons, who don't believe they have to run the full distance except on race day. I know one coach who insists that everyone training for a marathon has to go over the marathon distance during training. I don't agree with that, but you should have around 5 runs of 18 to 26 miles under your belt before running a marathon.
(I'm saying that as a chronically under-trained marathoner.)