First of all, I too get ridiculous motion sickness, but I take a Dramamine (one pill in the morning, works all day!!) and it works great!
Second of all, no kids - enjoy the thrill rides that may be too intense for kids, go to City Walk and go to Pat O'Briens for the Piano Bar, enjoy Happy hour in the parks, stroll around the lake at night.
Take your time....it's the best thing about USO/IOA - you can do it easily, and still get the most out of the parks!