Just to compare, so you have some reference: like you, I can't do spinning things (teacups are my downfall) & also have difficulty with simulators. I don't have a problem on Soarin', but can just barely make it through Star Tours at DL. CA Screamin' is out of the question after my first time on it was one of the worst I've ever had on a coaster, but only a wee bit queasy after Space Mtn - so I just can't do it twice in a row. Can do all others coasters with no problem & also no difficulty with drops, like Splash Mtn or TofT, even the old Maliboomer in CA.
That being said, I did Everest for the first time a couple yrs ago (foolishly thinking it was like Matterhorn) & after it started the backwards portion in the dark w/spiral, my cold sweats started & I just clung on & tried to control my breathing for the next 2 mins or so until it was over. I had to sit & rest for about an hour after. But I did do it first thing in the a.m & that might not have been the best choice. I don't think the backwards part itself lasted that long, but since it happened shortly after the start of the ride, it didn't matter. It was made worse I think by being in the dark & not being able to focus on any horizon for the remainder.
I did do Mission Space: Green because I had heard that it was fairly mild compared to what that used to be even & nothing like Orange. It's a simulator too, but wasn't super-jerky or anything. For me it was comparable to Star Tours, as far as it ended just in time for me & I was pretty much fine after. Whenever it got a little bad for me, I just focused on a fixed object in the simulator. Orange has g-forces I think & simulates being hit by asteroids and knew there was no way to get through it, so have never even thought to attempt it.
I also did Rockin Roller Coaster for the first time that same trip, although for the life of me I can't remember how I felt after - so it must not have been too bad, definitely nowhere near Screamin for me though. I had expected that one to do me in, but mainly I just remember the music being really loud!

I guess I must've focused on that instead & after doing Everest, it seemed mild by comparison. Also is a much shorter ride, I believe & that helped. It was over before I knew it.
The only other one I remember I rode for the 1st time & had been concerned about was the Test Track, since I wasn't sure what it did. In hindsight, all I recall is it being really jerky, with it doing quick braking & turns, bumps, but nothing that was hard on my stomach - only back & neck! Think of it like being a live crash-test dummy!
In case you didn't realize,
Youtube has videos of that & most other rides. That's a great resource for seeing what a ride looks like before you go - it doesn't give you the feel obviously, but at least lets you know if it has a "trouble" area for you. Some of the ones in the dark even have video taken with night vision so you can see them a little better. Just search for a ride name & usually the more recent ones are better to know what it's like now, since super-intense ones seem to eventually get toned down at Disney.
As a PP said though, you only really know how it affects you if you ride it for the first time. I know I'm surprised myself sometimes at what ends up making my motion sickness kick in, although it does seem to be more things the older I get.
I guess I never learn my lesson because I've got a trip to WDW starting this week. I plan to do all of the above again, just once - people & rides do both change and now I know better what to expect. I am also bringing ginger chews to combat the effects of the milder ones. They don't help with dizziness but are great for nausea. Just will pop one in as I start the ride. Am also going to be taking Meclizine (generic of what's in Bonine) every night to keep a steady dose in my system. For most people, it's much less drowsy than Dramamine which has a different drug in it & especially if you take it every night instead of daytime. We'll see how that works out. Fingers-crossed. Now for our day at Universal, bringing out the big guns & using the Scopolamine patch instead - otherwise, can't ride anything over there!