I also find if I relate to my kid not as a defiant, difficult or aggressive child but rather a child with difficulties poor coping skills and other challenges , it helps me to cope better , not be in a confrontation, quick fix mode, be calm , respectful and creative in my thinking. It is so tough and stressful and the negative thoughts are understable , but they usually interfere with my positive outlook and happiness.
I agree so much with Allan in regards to the above, tho this is hard to do. I hope something helps, I do not have experience with teenagers, and dread those years. Make sure to find some time for yourself somewhere, you must be busy.