Dude, you will keep beating yourself up if you don't tell her!!
It will eat you up.
Just think: she deserves the truth. Also, it is quite a brave act to tell her.
I know this is cheesy as hell but, if you can't bare to tell her in person, write her a letter. Personally, letters get to me because there is just something so genuine and personal about a hand-written letter.
Telling her how things look from your perspective will give her a new way of seeing things which she needs and, hopefully, a realization.
But, before that, just make sure she is the right girl and you aren't hurting yourself. Some girls don't know what type of guy is right for them, while the right guy is literally right under their noses. Before persuading her that you're right for her, make sure she is right for you. :thinking:
Good luck!