I need help please what should i do?

I have been friends with this girl for 13 years and things has started to change. I have realized that I have begun to get feeling for her and I've talked with her about it and she says she feels the same. We have both expressed our feelings for eachother and it turns out we wanted to be more than friends from the beginning. she told me that she has been talking with another one of my friends and I dont know if I should keep trying for her. She says that she's afraid and she doesn't know what she wants. We have been been best friends for years and I don't know if because she told me she is afraid if that a sign to back off. I was going to move but she asked me to stay numerous times. We both tell eachother that we love one another and that its more than a friendship or brotherly love. I express how I feel to her all the time but I'm afraid I'm trying too hard and when I tell her I feel like I am trying too hard she tells me I'm not. I'm just really hoping things workout but I feel like I don't know what else to do. Please if anyone can give some advice its appreciated.