Don't beat yourself if you find you're not always a shining beacon of wisdom. Going through these moments are, too, a way that you continue to grow in wisdom.
To me, loving animals is not just only about how they make us feel. It's an act of seeing them with as much compassion and clarity that we can at the time.
It's easy to dread interacting with some of these people. Often, we can't avoid them--especially if they are a boss or a family member. I find this helps.