Do i have the NICE GUY syndrome?

Ever since High School i've been more insecure and i've been nice to girls all the time but i still act like my self with them everything in my personal likes and what i don't like. Although extremely attractive girls i like i get nervous and i always act nice they could probably get me to do a lot of stuff but simple things like getting their book, opening a door for them, but not anything like stealing or violence just by asking. It's until i get to know them more or when they explain about their problems, emotions, etc i open up myself and i feel comfortable around them but i'm afraid that we will lose contact but i would never tell them that and i would act like i was okay with it because i think this is my syndrome. I want them people in my life especially the attractive girls but i don't have to be dating them i just want them to be a part of my every day routine at school even if it's like 5 minutes of talking. It does make me feel self fulfilled and it encourages me to try new things out, workout, makes me happier. I've never had a previous girlfriend before either. Ever since i've been working out i've been proud of myself and i feel more self worthy because i feel like i'm improving myself to become an image i daydream of myself i could be