This is a good insight. You are like me. I taught (!) fulltime for several years, at great cost to myself. It was like playing a role all day, and I am not a natural actor type! I learned a lot, but believe I would have learned more of value applying that effort to something more fitting. Get out and find yourself a field that suits your personality. We aren't all sales types, despite that our society is geared that way. Just say no.

The job doesn't fit you, and you don't want to fit yourself to it. Fair enough, and case closed - next. Just my viewpoint. Perna makes many valid points, as well. It is entirely your choice what you do.