It's not a trust issue.... it's a shame issue.
I used to say I was timid... because I was so closed off also. But I too realized it was just as you describe - a feeling they will be disappointed with me, find me bland, and perhaps reject me or just have an indifference to me, meanwhile, I may have grown attached to them. I'm always afraid I will care more for others than they care for me, so it's easier to keep them at arm's length.
This is not timidity, because it's not fear of them. I don't fear them as if they could have some malice, because I see the flaw in myself. It's really a shame over who I am, that I am not significant, special, interesting, etc, enough to be valued as a friend.
From wikipedia:
"The roots of the word 'shame' are thought to derive from an older word meaning 'to cover'; as such, covering oneself, literally or figuratively, is a natural expression of shame"
"Such shame cognition may occur as a result of the experience of shame affect or, more generally, in any situation of embarrassment, dishonor, disgrace, inadequacy, humiliation, or chagrin"
"...shame arises when one's 'defects' are exposed to others, and results from the negative evaluation (whether real or imagined) from others..."
"While guilt is a painful feeling of regret and responsibility for one's actions, shame is a painful feeling about oneself as a person"
"Shame is an acutely self-conscious state in which the self is 'split,' imagining the self in the eyes of the other..."
"Kaufman saw that mechanisms such as blame or contempt may be used as a defending strategy against the experience of shame and that someone who has a pattern of applying them to himself may well attempt to defend against a shame experience by applying self-blame or self-contempt. This, however, can lead to an internalized, self-reinforcing sequence of shame events for which Kaufman coined the term "shame spiral""
"A person who feels guilt is saying "I did something bad.", while someone who feels shame is saying "I am bad"."
It's good to get to the root of the shame, then. Begin exploring why you feel irreplaceable and not very special. Also replace negative inner dialogue with positive dialogue. It can help to develop some personal mantras that reinforce a more positive self-view. I started once with "I will be nice to myself", and I would reject any inner voice which said things I would never say to a dear friend. So start to value & treat yourself as a dear friend, and then it will be more believable that others can, will & do see you that way. You can't trust they do now because you believe the shameful feeling is the truth, but it's a distortion.
