You and I both know that just because someone knows how to do something well, doesn't mean they can teach it effectively. I've spent a good part of my life teaching people how to do things and I can confidently say, it's a separate skill. I've been to hundreds of classes, seminars, workshops and camps. In the teaching arena, at each of these events, there is wheat and there is chaff.
It's certainly alright to be a beginning teacher who is unsure of the most effective methods, feeling your way through and learning from experience. But there's a big difference between that and someone who is just not meant for the profession. If you are not a lifelong learner, if you cannot relate to each of the learning styles in some way, if you prefer not to work on the craft of teaching, you should probably get out.
It sounds harsh, but look, we're all good people. I'm not idly casting aspersions here. I'm simply saying that if you consider teaching anything less than your life's calling, you are doing damage. You need to make a shift; to find another way to make a living.
At the High School for which I taught (and most public schools, I think), there was a legion of teachers who were simply trapped by their decision to teach. They knew in their hearts that they had made a poor choice of career, but were too petrified to stop and do something else. So instead, they showed up everyday and went through the paces, giving their students their minimal effort and negative energy. The problem is, of course, that uninspiring teachers create uninspired students. You have to care at a level that most people just aren't built for in order to excite and mobilize a class.
It's okay if you don't. It's not a bad thing. you've learned something valuable about yourself and now you can move on and let someone who is more passionate step in and fire people up. It doesn't mean you've failed. In fact, in many ways you've succeeded. You've acknowledged your unhappiness and now you can shift gears.
For those who may be considering stepping into the classroom, a word of advice. Just make sure you want it more than anything else. Make sure it's not your ego that is driving you to teach. The least effective teacher in the building is the one that wants to "pass on their considerable knowledge". It's not about you. It's about the people in front of you. Keep that in mind, and we'll all benefit from being in your classroom.