I liked this article in Lions Roar, it’s Pema Chodron talking on heart qualities.
The natural warmth that emerges when we experience our pain includes all the heart qualities: love, compassion, gratitude, tenderness in any form. It also includes loneliness, sorrow, and the shakiness of fear. Before these vulnerable feelings harden, before the storylines kick in, these generally unwanted feelings are pregnant with kindness, with openness and caring. These feelings that we’ve become so accomplished at avoiding can soften and transform us. The practice is to train in not automatically fleeing from uncomfortable tenderness when it arises, and with time we can embrace it.