It's ok, you haven't discovered them yet, you have lots of time for that and you'll be simply amazed then, but your teacher should have chosen a different career. She definitely wasn't where her gifts were.
All human beings suffer of some kind of medical condition at some point in their lives, being that physical or psychological, but most probably both. From a simple cold, to diabetes, back problems to addictions, tendency to depression, etc. Our self-healing capacity is limited (yet) so we all need a visit to the doctor and treatment when we aren't functioning the best we should.
There is no such thing as ''normal person'', whatever that may be, because we are all struggling sometimes to find a sense in this imperfect material world. We are the brave souls who have undetaken the continuous challenge on this remote planet trying to achieve control of the matter through our physical bodies and there's no other sense in this life than keep on trying the best we can and helping each other.
The sadness, pain you experience are not who you are, they are just symptoms of a medical condition that can be treated, the same way you'd make sure to follow a treatment for any other health problem that you could have.
I agree, we can't all be like John Nash, or Mother Theresa, but we can all do something good in our lives :-)