Some of those woozy feelings can be due to a lack of caffeine (if you drank it) and/or sodium. You just have to get thru it if its caffeine withdrawal. But, you can add a cup of beef or chicken broth to get a dose of sodium, which might help.
How long you'll be on the pre-op diet is entirely up to your team. I did 2 weeks pre-op. Then 1 week each of clear liquid, full liquid, puree, and soft. My hubs did 3 weeks pre-op. 1 week clear, and 2 weeks each of full liquid, puree, and soft. He had the sleeve, which usually involves a longer restrictive diet due to a larger wound in the stomach.
Keep it up! You guys are doing great!