Without going into any detail, this has happened to me quite often with various people. The bottom line is that people change and their circumstances change over time in one way or another, and change will always have an impact on relationships/friendships. It is possible that both of your needs were more compatible in the past, but now some of her needs have changed or have been fulfilled, and so she is no longer seeking as much from the friendship with you. I know that is an unpleasant reality, but this has happened to many of my past friendships. Friends have become distant or completely vanished when they didn't need me as much anymore.

The only variation is in how a friend pulls away. Someone who is primarily a user, will not care how it affects the person being pulled away from. Their attitude will rapidly become very cold, and any attempt to explain how you feel will likely just annoy them, and cause them to say something hurtful or exit even faster. Many of the user types will find some way to blame you for the ending or distancing of the friendship. They will not admit any responsibility for it, or acknowledge how it has affected you at all. A person who has more integrity and compassion for others, will find some way to stay in the person's life and continue treating them with the respect they deserve. At a minimum, they will explain what has changed, and make it clear that it has nothing to do with anything you've done wrong.

Anyway, I truly feel for you, because I know how hurtful a situation like this can be. I can accept a friend changing or a relationship needing to end, but I don't accept being treated like my feelings or dignity doesn't matter anymore, or apparently never mattered. However, in the end, there is nothing that can be done about it, even if I don't accept it. I just have to suffer silently, until the painful sting diminishes somewhat.

Unfortunately, some people don't show their true colors until we have already learned to trust ourselves to them.