Tell her you love her and want her to have what is best for her but that you cant have a relationship this way. Ask her to take some time to think about it and that you will be doing some thinking too. Then get out with your buddies and try to have some fun or at least to keep busy. Once she no longer feels committed to you and knows you arent there to do her homework, she may realize that she does want you still in her life. Or she may not but if you take the step it will be easier for you cope no matter what the result.

No matter what you need to keep busy with what you have to do and stay on track with your life.