For me, writing helps a lot. I keep a blog that I have been writing in for about 3 years now. Its not only beneficial for me, but lots of others read it as well and gain some insight into themselves.

You mentioned a self fulfilling prophecy. I think you are not too far are the mark here. Though I tend to refer to it as a curse.

People try to put curses on us all the time. Curses like;
You are not good enough
You will never marry
You are no good
You are crazy
You are an Avoidant
You will never be good enough
and on and on

It is a bit though like self fulfilling prophecy. We tend to become like what we are told we are, or should be.

The good news is that we dont have to. We can deny all that and be the person that God told us we are. Sure there are issues due to us living in a sinful world and us being in this fallen state. But that does not mean that we have be defined by it.

We are good enough
We can get married
We can have relationships
We can be successful
We can have friends
We are interesting
We do have much to offer
and on and on