What should I since my best friend knows that I like her? ?

Awhile back I had meet this girl by chat we soon became best friends and found out that we have a lot in common, soon she called me her twin and she called me the brother she wished she wanted but that came in as a fear because I wanted to be more than friends, she knows that I like her but been trying so long just to see her but then soon saw her by luck, but the thing is should I just move on or try a little bit more because I find in my heart as a person I could share my life with, but in my mind I just think I am just wasting my time, what should I do?