You sound just like me. Honestly what I do in situations where I know I may or may not panic about it (movies, restaurants, car rides, etc) I keep my "kit" with me. Ginger candy, peppermints, peppermint oil, and I never take off my SeaBands. What you can do if you panic about sickness is to press on an acupressure point in your wrists (I'll explain the exact spot in a minute) that's known to ward off the feeling. SeaBands are basically a wristband that has a ball in it that sits on that acupressure point all the time, it's really good for pregnant women or people that get carsick or whatever (they're maybe 5 bucks at Walmart). If you take three fingers and place them on your wrist, you want to push on the spot where your third finger would sit. That probably didn't make a whole lot of sense, I hope it did, but it's a legitimate pressure point to cure it so googling those pressure points is probably a good idea. Also I've noticed that having something to squeeze helps me stay distracted. My wife gave me what she called a "worry stone" that I would hold and rub my thumb across whenever I panic, and she says that rubbing it takes the worry out of me and puts it in the rock. I still don't leave the house without it. What I can tell you for sure is, nothing about sitting in your house with your friend is going to make you v*. That's physically impossible. So just try to keep in mind that you're safe if you start to worry and that you're literally not doing anything that could possibly make that happen. Have a good time with your sleepover, hope that helped.