Lebanese poet-philosopher Khalil Gibran, in 'The Prophet' has beautiful advice in reference to detachment in relationships:
"Let there be spaces in your togetherness, and let the winds of the heavens dance between you. Love one another but make not a bond of love. Let it rather be a moving sea between the shores of your soul. Sing and dance together but let each one be alone. Stand together yet not too near together, for the pillars of a temple stand apart and the oak tree and cypress grow not in each other's shadow."