Today I rode all the roller coasters at elitches. I'm trying to sleep but I can't because I still have the sensation of being on a roller coaster. How to I stop this feeling :(? Or make it more bearable

Go get some Dramamine (for seasickness, same thing).
Go for a walk if you can. Your eyes seeing what's moving past you slowly will help your brain adjust.
Read, watch TV, if you can't go for a walk. You can't roller coast all day and expect to just go to sleep.