The reference would be, among others and perhaps better than any:
1 Cor 13:4: Love is patient, Love is kind. Love is not boastful or envious or arrogant or rude. Love does not insist on its own way; it is not irritable or resentful; it does not rejoice in wrongdoing, but rejoices in the truth. It bears all things, believes all things, hopes all things, endures all things."
In short, love is choosing; and it is a choice made for the other as against a choice made for self (aka a selfish choice).
You will notice that nothing of St. Paul’s statement has to do with emotion; it is all about choosing to do good and being other directed rather than self directed. That is why it is said that love is self-giving.
Emotions are most definitely not self giving; they are all about self and how the self feels.