I can kind of see where she's coming from. I have always been a sort of shy and withdrawn person, and I know how hard it is to come out of that. I wasn't to the point where I wouldn't tell someone I love them, but I wasn't very good at expressing myself.
Let me just say that you probably should not be trying to pressure her to get to your "emotional level." that's not fair. That's obviously a long way for her to go, and you're likely to push her farther away if you try too hard to drag things out of her.
Second, you can't force her to tell you she loves you. Just keep saying it to her; ask her if she loves you, even. But don't try to make her do it. She's only going to end up resenting you for that.
Third, you .H.A.V.E to continue to tell her that you will love and support her no matter what and that she shouldn't be afraid or embarrassed to say anything she feels. Tell her that all you want to do is make her happy and that you can't do that if she doesn't tell you what makes her happy. Tell her how much it hurts you that she doesn't open up to you... But tell her that you love her anyway and that you just want to know that your feelings are being reciprocated.
Lastly, above all, no matter what she says to you, even if it's not what you were hoping for, you .M.U.S.T be receptive and positive. If not, she might never open up to you.