Time heals the anger, but it doesn't remove the feeling of betrayal, or offer consolation. 

Depression leaves a feeling that you made some critical mistake of judging character. How could you be so naive? How could you leave yourself so vulnerable? How can my efforts to give so much be discounted and how can anyone be so willing to hurt to the core and do so without any apparent effort?

It always helped me when I accepted the illness is stronger than anything I can do. It's a humbling thought and it made the anger less severe. 

As far as conveying the anger: decide if that's what you really want. A depressive can be oblivious of the carnage their illness leaves. Letting it go and refusing to hurt another to validate your emotions is much better.