I don't know what to do next

I've been communicating with a girl for five years. She is attractive, kind, smart, cute and just lovely. When we made friends at school I was about 13 now I'm nearly 18 and I still really love her. During the first year of our friendship we talked to each other sometimes and as I suppose were interested in each other. In the second year one of my friends fell in love with her and I (don't know why) didn't resist because thought that it'd be better for her. However, they broke up the next year. The third year was full of troubles and problems in my personal life and I didn't have time for full relationships. I decided that it wouldn't be correct to start everything from the very beginning during this hard time. Nevertheless, she sometimes tried to turn my attention to herself but I didn't respond purposefully. The next year was much easier for me but she was already with another boy with whom I decided to become friends too. I don't know much about their love and whether it was mutual but what I know is that this boy liked her a lot. In the following year our relationships with her blossomed and we really made great progress in attempts to attract each other. In the beginning of this year she and this new friend broke up and I thought that the time came and started to try to be closer to her. We now text to each other regularly and she is much more communicative online than in face-to-face conversations. It's a problem because it seems that she tries to avoid me in real life. When I make an attempt to start a talk, she usually closes up. Maybe, she thinks that it's easier for me to speak less (because some time ago I was really timid "good boy". Now I grew up and behave, I think, as a man should). But I see in her eyes that she is willing to talk. Nonetheless, this type of communication is not the worst thing to happen. I asked her out several times and she always told me that she was busy. I think that she's afraid of going to some distant places because when I asked her out to the park nearby her home she agreed. The stroll was short but it's something already.
Last week I decided to tell her that I like her and even wanted to work out some plan how to reach the goal.
But yesterday she asked me a question about their fall out with this last boy. The question was disguised but I got it quite well. Now I hope she won't reunite with him again. It's the first time I tell this story.
I truly love her.

What should I do? Should I reveal my feelings to her or is it too early/late? Is it better to wait more?
What do you think?
Sorry for my English ><