Hi there,
I went alone in Early June, and had a great time. Take this trip to explore and enjoy things you might not ordinarily have time to do - I found this especially true in the World Showcase. You're the boss, so you shouldn't have any reason for not seeing or doing the things you want to.
As far as dining goes, I've always enjoyed eating out by myself, so that wasn't uncomfortable for me and I love to watch people interact with one another. If you think you might feel strange sitting in a restaraunt alone, you can always just do fast food stuff and eat on a bench and people watch.
Take advantage of any and all single rider lines. Don't be afraid to strike up conversations with other people in line or cast members. All in all, treat yourself like royalty - you deserve it!