Never become a poor little guy that she will have to take care off. Just be yourself and if you'll become a stalker, don't let her feel that. Don't do anything that can hurt her.

In my opinion you should just seriously talk with her. Meet her somewhere (it should be quiet place) where you can just talk and tell her all that you feel for her. Tell her your worries and your hopes and ask her what does she feel. If she'll say there is no way that we can be together, then don't just runaway, but ask her why. You can expect that much from a person you are considering your friend. If there is no way for you to be together then ask her what in her opinion you should do. I think that people asks too much for help in here, while they should talk more with the ones they love. After all you want to stay with that person for the rest of your life. You should be brave enough to honestly talk with her. If she feels anything for you, she won't laugh but talk with you seriously.