I’m convinced that, for me at least, it’s not possible to feel love and fear at the same time.
On reflection, that makes sense. Fear and love are opposite emotions. Fear arises from our aversion, our rejection of potential outcomes, our unwillingness to accept people or what they might do or say to us. Metta is a boundless friendliness that arises when we cultivate good will toward ourselves and others and allow people to be who they are. Fear closes us off and traps us in our conception of ourselves as isolated, vulnerable, wronged. Metta opens us to the experience of our connectedness, to our common birthright of love. Fear says “no” to life; metta says “yes.”
The Karaniya Metta Sutta, one of the very early texts in the Sutta Nipata, makes the contrast plain:
Cultivate an all-embracing mind of love
For all throughout the universe,
In all its height, depth and breadth —
Love that is untroubled
And beyond hatred or enmity.