You're using a Sony point and shoot in the panorama mode?
The camera did a decent job stitching them together, from what I see.
Yes, they're overexposed. Your ISO is up at 1600 for these, at least the exif says that. I'd try to keep that much lower in the future. Most compact cameras don't take very high quality pictures at anything above 400 (at least the ones I've used).
Another thing, venture out a little. Pictures of the backyard are great if you want to sell your house. New Zealand has to be one of the most beautiful locations on our planet, let's see some of it.
My advice is to learn how to use your camera in manual mode, practice until you're getting some good and consistent results. Once you're comfortable with that, put some thought into what you're photographing and the placement and position of your subjects.
Hope to see more from you, good luck!