Seriously considering it

A half-marathon, that is. There's a local one in 9 weeks. I just so happen to have a 9-week training plan downloaded. I'm scared slap to death to commit to it. I'm sure that's normal, though, for people who have never done a half. I think I'm most scared of taking longer than 3 hours to do it. But, I can do 5 miles in about an hour, give or take a few minutes, so logic says that I should be able to do 10 miles in about 2 hours and then 3 more miles after that, so around 2.5ish hours. Still scares me. Like butterflies-in-my-stomach-already scares me. I think I am going to do the first week of training and then register. Maybe it will be what I need to break through my stinking weight loss plateau.