Stop comparing yourself with others. If they are good at something, you too are good at something else. Self-confidence is not measured by your own capabilities versus that of others, but by your own needs.
There are no coincidences in life. What person that wandered in and out of your life was there for some purpose, even if they caused you harm. Sometimes, it doesn’t make sense the short periods of time we get with people, or the outcomes from their choices. However, if you turn it over to God he promises that you will see the big picture in the hereafter. Nothing is too small to be a mistake.
You will not be punished for your anger, you will be punished by your anger.