Self-esteem is a good opinion of yourself backed up by genuine accomplishment. It is essential to success in any facet of life.
Egotism is an inflated opinion of yourself, usually based on nothing more than never having run into a situation where your abilities or opinions are subjected to a critical review by others. It's what makes the American Idol tryouts are so amusing.
Big Religion likes to confuse the two concepts, because people who develop genuine self-esteem no longer have much use for it.
I believe this is the working definition used earlier in this thread for the term "self-respect."
I think the difference lies in deciding exactly what we intend the term "self-esteem" to mean. As I see it used by the education establishment, it appears to mean something different than your definition...in fact, it appears synonymous with "ego," because that is what the local public schools are achieving.