I have no patience or kindness anymore

I've only been teaching for six years. I used to love it. And I'm really good at it. But I think I hate the students now. I teach secondary English and health and I'm just so done with the students. They make me so angry. So sad. Frustrated. My immediate reaction is to be angry at everything they do, everything they say. I immediately jump down their throats, like I have no patience or empathy left. I don't want to change careers, I want to love what I do again. How do I stop being mean to the students? How do I change my perspective?