It seems to me that goodwill or benevolence makes for a more accurate translation that correlates into this physical reality.
Metta can't be a loving feeling, love in Pali is pema.
When I concentrate my mind on benevolence, goodwill, wishing that a being may be happy and healthy I feel less attached and happier myself.And how is hate born of love? It’s when someone likes, loves, and cares for a person. Others treat that person with disliking, loathing, and detestation. They think: ‘These others dislike the person I like.’ And so hate for them springs up. That’s how hate is born of love. - AN 4.200
When I concentrate my mind on love for a being sometimes it makes me feel upset and angry, it doesn't feel right.
Some of the suttas also support what I thought that metta more translates to wishing well, that all may be happy, like benevolence.
A way of objectively measuring if metta is developed is given:
This seems to imply that metta is the opposite of ill-will or byāpādo like goodwill or benevolence instead of loving-kindness.Take a mendicant who says: ‘I’ve developed the heart’s release by love. I’ve cultivated it, made it my vehicle and my basis, kept it up, consolidated it, and properly implemented it. Yet somehow ill will still occupies my mind.’ They should be told, ‘Not so, venerable! Don’t say that. Don’t misrepresent the Buddha, for misrepresentation of the Buddha is not good. And the Buddha would not say that.
It’s impossible, reverend, it cannot happen that the heart’s release by love has been developed and properly implemented, yet somehow ill will still occupies the mind. For it is the heart’s release by love that is the escape from ill will.’ - AN 6.13