With mindfulness, loving kindness, and self-compassion, we can begin to let go of our expectations about how life and those we love should be. - Sharon Salzberg

The Buddha actually described at some length what he meant by being a good friend in the world. He talked about a good friend as someone who is constant in our times of happiness and also in our times of adversity or unhappiness. A friend will not forsake us when we are in trouble nor rejoice in our misfortune. The Buddha described a true friend as being a helper, someone who will protect us when we are unable to take care of ourselves, who will be a refuge to us when we are afraid.

As an ability, love is always there as a potential, ready to flourish and
help our lives flourish. As we go up and down in life, as we acquire or
lose, as we are showered with praise or unfairly blamed, always within
there is the ability of love, recognized or not, given life or not.

With attachment all that seems to exist is just me & that object I desire.