I've had a slightly similar experience with a friend who told me that she "couldn't be as good as a friend as she wanted or I deserved."

It significantly hurt me because I was dropped as a friend after I knew her for 3 years. She also didn't give me a legitimate reason. We often seek reasoning in acts of cutting off friends. Another friend told me that she probably developed feelings and couldn't handle me not seeing her romantically.

Regardless, you are absolutely in the right for being everything that you could be as a human. You did everything right and she has her own problems that she may have felt she needed to have overflow onto you. Sometimes we react in anger and it can affect onto others.

Silence is awful. It is hurtful and it is especially hurtful to those have have mental illness. Communication is the best one can do, even when it is to say that you need space or silence.