I’m so sorry. I suspect the cycles a person goes through take long periods of time to resolve.
There will be rough days like you experience and it’s easy to get stuck in thoughts that can bring you down. Take time each day, even if a few moments, to sit in silence and focus on the emotion you are feeling. Practice feeling it fully and then letting it go. Hold a picture of your friend, go to a place of unconditional love and repeat “I forgive you” while sending her love.
I am sure she does know you are there for her. Sometimes people aren’t in a place where they can receive it at the time. During those times, trust that the person’s soul receives it and let go of the need for a certain outcome. Love because it is who you are.