lightthecandle-
What needs will your friends fulfill? Your need for acceptance? Your need to be loved? Your need for approval?
These needs are hard to fulfill. Sometimes even having friends won't fulfill all of them. I think the source of the problem is the presence of these needs. They're hard to fulfill because only a 3rd party can do that. One is essentially placing their emotional well-being in the hands of another person by holding onto these needs.
I love
this article and
this one in regards to this issue.