Love is not just nice, warm feelings. Love often includes our emotions. But it is not only, or even primarily, an emotional thing. In the way that 1st John means it, and in the way which thoughtful Christians have interpreted it, love means walking the way Jesus walked. Walk with Jesus, and you'll learn about love.
Love means living as a branch of the vine.
Love means opening ourselves to the Spirit which Jesus had. Love means choosing, often in the face of what seems to be an easier and more sensible alternative, the difficult and more painful way of peace. The violent response is often the easier one. Violence, or the thought of violence, often makes us feel good. You don't always have to think.