It would make some difference if you did not acknowledge her needs because you did not know of them or did not know how versus you ignoring them. Partners learn about one another and themselves throughout their relationship. You could have not read her mind as far as what she wanted and needed. At that stage in your life together, you did the best you could.
She has the right to feel the way she does. It is her subjective interpretation of the events. If she chooses to get stuck in the past, there is not much you can do to "change her mind" She has to be willing to give you a chance. What you can do is continue to work on yourself as you've done with the 180 turnaround, respect her feelings (even if they are not beneficial to you or the marriage) and let her know that you are willing to at least give the relationship a chance before she decides to do otherwise.
Of course, she has the right to refuse. She may fear that your change is a temporary one. As far as being "late" ask her what this timing means to her. If she truly believes that she is not in love and wants another life, there is nothing you can do to change her mind. She knows what makes her happy or what she wants out of life and a partnership. If she agrees to give the relationship a chance, then serious marital counseling would have to take place. Ask her what does she want and need and what is she willing to do, and take it from there. There must be at least one thing that she could allow herself and you to try.