Found the right girl at 17 ?

ok heres the deal. My past relationships have gone down the crapper and ive been left pretty hurt (cuase im a softy lol dont judge). So at the moment ive been spending alot of time with my best friend, we are both the same age and we already no tht we are both interested in each other. The only problem is, is that im scared of commiting because of loosing her as a friend or hurting her and/or me. Also the thought that i could easily spend the rest of my life scares me at this point in my life. Also my feelings for this girl arent exactly clear, but this could be due to the confusion in my mind. This is a real painfull decision and just asking for some advice whether or not to take the plunge?? Any other opinions would be great as well.