I think I'm falling for my best friend?

I think you should go for it. It sounds like you guys have a solid relationship together as it is and even if the dating relationship should fail, you guys will still remain in tact and be just as good of friends. You just need to take the initiative and make the first move, she told you she has feelings for you so if anything it would make it more awkward if you were to not act on this because you feel the exact same way. You obviously both really care about each other and will always continue to respect one another. I don't see any reason why you shouldn't start dating, best of luck.