What is the opposite of love?
Loving kindness(Metta) is a state of the mind that arises and vanishes. It's not something that exists. For loving kindness to arise, one should see the lovable nature of beings. It does not require suffering. On the other hand, compassion requires seeing the helplessness in those overwhelmed by suffering.

Happiness is also a state of mind that arises and vanishes. It does not require suffering. Happiness arises even in the minds of enlightened beings.

Far enemy of love is hatred/aversion. Near enemy of love is lust.