Why am I doing this?

I know you say that it is because your afraid of rejection but what if it is? Or maybe your just nervous. Just go for it the worst that will happen is she would say no lol and if she does then she isn't worth your time : )

I think that you are actually more connected to her than you may know, I mean it could be that you actually feel something deeper for her than just another crush. I don't mean to say that you LOVE her, just that you have found a person with whom you connect.

And don't worry about walking up to her and saying simply "I like you" that leads to some weird things. Let her know how you care, but perhaps in a more subtle way.
If you are interested in dating, let her know that, and perhaps even ask her out.

Perhaps you feel, that because there is more to this relationship that you might be wiling to admit, that you are actually afraid of what she will say. It is deeper rejection than you are normally used to. It is more than superficial. Doing something once, does not necessarily make you immune to the effects of fear.