Is normal a teacher went out of a class, asking "was I born to be a teacher?" after a stressful class for kids. - It never happened to me b4?

Yes, it is normal. Sometimes I would lay my head on the desk so the class couldn't see me laughing when some of them gave really ridiculous answers. In one of my classes one student gave a such a bizarre summary of the chapter that I had to ask if we were reading the same novel.

One of the most gratifying moments in teaching is when at the end of the term during last class, the entire class of students stands and applauds the OldProf.

On the flip side, one of the most depressing moments is when at the end of the term during last class, one or more students shared they thought there be more about project control Why? Because the entire term was about project control and these students didn't get it.

Both cases happened to me for the same course, but two different classes at two different universities.

My point, class dynamics are harder than hell to figure out sometimes.

When that happens, think of the good moments. Also reflect on what could have been done differently and implement this next time. Your colleagues will also be happy to help as they will have faced this too. Take care