If your boyfriend works on improving himself as a person, he will experience a boost in self-esteem, which will make him feel more "deserving" of a good catch.
Does he engage in any activity that allows him to view himself as a good, worthy person? Is he educated?
Also, I think insecurity is a symptom of youth, and to a large extent one outgrows a certain amount of this, assuming a normal process of maturing...
Relax... I'll need some information first. Just the basic facts - can you show me where it hurts?