Have you ever considered using negative energy and converting it into positive energy?
If you felt "not good enough" in something(personal qualities etc), could it be possible to take as a challenge to do something that made you feel confident? It doesn't have to be the best result, just that you became proficient at it.

For example, I wish I could speak more languages because now, the motivating issue is to understand that small phrase or characteristic of a language that makes it colourful(colourful in terms of interesting, appealing, not cuss words.)