Teaching is for when you can get nothing better to do.
The above is simply what I believe; I'm sure the vast majority of people will disagree, and that's perfectly okay with me.
The majority of people disagree because it is a truly cosmically stupid and ignorant statement. Tell it to Saint Ansel whose workshops inspired hundreds of photographers over many years (yours truly among them).
The fact is that in any field of art, supporting yourself solely by selling your work or talent is very rare and difficult, and depends as much on luck, contacts, and self-promotion as it does on the quality of your work. I mean, look at the dreck being sold for large amounts in some galleries in NY and elsewhere, or the many photographers making a living with "calendar and greeting card" crap.
Many highly talented artists teach because they love working with students. It can also be a way to pay the bills to allow you to pursue your passion.
It's unfortunate that you did not have better teachers.