Jennifer, I hope you don't give up. I was just going to offer some empathy. I'm a racing novice too and felt exactly the same as you after my first half marathon a couple of weeks ago (Sheffield). I went out too fast, got too hot, ended up run/walking the last couple of miles, really didn't enjoy the bulk of the race and finished in 2.17, which was about 10-15 minutes slower than I thought I should have done.
The cure? A couple of weeks on I've been out for a couple of watch-free, scenic runs whilst away for the weekend...just for the joy of running. And I've remembered why I enjoy it. Even if you can't go away somewhere scenic for the weekend, you could try going for a run somewhere new and possibly attractive and try to put the fun back...
Oh and pat yourself on the back for being able to run a half-marathon at all. If you're a novice, I bet you couldn't do that at all a few months ago. I know I couldn't.