Congrats on moving up in your distance running! How exciting! You are definitely not crazy - there are many of us out there
I have run at least 7 or 8 half marathons, a couple of 20Ks, a 25K and countless shorter races. I am signed up for my very first trail ultra marathon (50K) this spring!
Running has become a part of who I am. I no longer see it as something that I have to do, but something that I want to do. Of course there are always going to be bad runs and bad days, but I really do it enjoy it for the most part.
The actual day of your race should be a celebration! It is what you have trained for...what all those miles have been for...HAVE FUN! Don't have a time goal for your first half marathon or marathon - just enjoy the atmosphere and smile for the cameras. I had an absolute blast during my first half marathon. I think I grinned the whole time. There will be plenty of other races for time goals, etc.
I am a regular over at the Runner's World forums. Come visit us at the Beginner's forum - you'll find lots of support and advice over there for your first half.