Complicated
You tell her you don't want to complicate her life, and you mean it. She has so many things to deal with: her studies, her friends, fighting demons and hacking into the Initiative. She was accepted by every university with a stamp, including some overseas: there must have been reasons to stay here. You don't figure in any of them. She's smarter than you, prettier than you, and you know you should just step away.
You say you don't want to complicate her life, and yet you ache for her. You know you will make her life easier by leaving it, but without her, you feel as though life is nothing. When she says she hasn't seen snow, or the Sierra Nevadas, you want to be the one to show them to her. When she says she's never had a kitten, you want to buy one, right then. You want to give her diamond sunbursts and marble halls, and build a life together. All three are equally impossible. To let her go would be your ultimate sacrifice. You're not sure you are able to do it.
You don't want to complicate her life. By telling her so, you just did.