Hi, I'm A 23 Year Old Female And I Excercise

Hi, I'm a 23 year old female and I
Excercise 5 times a week, I eat organic food, I don't smoke or drink, I don't share food or drinks with anybody and I wash my hands about 3 times a day. But I am ALWAYS sick with colds whereas all 20 of my close friends don't work out, hardly wash their hands, & (for the most part) they all smoke and drink. What is wrong with me and why am I always sick with colds or bacterial infections? What can I do to change this? Thank you.