Yeah, I'm 19 too and I'm kinda the same. The Norovirus scare cropped up for me only a couple of days ago since that's when I found out about it; I've always had a phobia of sick but it's since last year that it's been playing on my mind. With this Norovirus going round I'm trying my best to avoid it and that's the most you can do really... wash your hands with warm soapy water or hand sanitizes, try to avoid contact with those who have it or have recently got over it. I know it looks scary from what's being said in the media but just try not to worry! I'm nervous myself but I've been able to control it; I can still go out I just make sure that my hands are clean.