Its OK!!! I think everyone gets sick at some point during 1st semester. I didn't eat for two days after my inserting my first NG tube.... Lets just say that I never believed the term "projectile vomit" was truly accurate until that day.

You'll get used to most stuff pretty quick, but there'll always be something that bothers you (thick, nasty, multicolored mucus) but just keep in mind that everyone has been there too.