Thanks for all the replies! It does help to see other peoples experiences/ideas etc.
I wish I didn't have to have this conversation with her at all but it is bothering me so much that I think about that more than anything else. There is seriously not a single day (sometimes hour) that goes by that I am not thinking of her in one way or another - this can not be healthy. I don't know if telling her will help with that but at least I will get it out I guess.
I have started writing it down but am still really stuck for words. Part of me wants her to push me away and refuse to see me anymore just so I can move on and forget her (I've never felt like this before with anyone else) - the other part wants her to accept it but I doubt I'll ever be ok with it after I tell her so I wonder if it is worth the heart ache? I wonder if I should just tell her and leave and not wait for her response? I just know I am going to be so embarrassed after telling her.
I want this over with!