Have you considered getting therapy? I'm not (just) being a dick, therapy really can help a lot and you seem to have a lot of inner conflict around vulnerability.
Speaking of which, have you seen Brene Brown's great talk on vulnerability?https://www.ted.com/talks/brene_brown_on_vulnerability?language=en
Have a look at Amy Cuddy while you're at it:https://www.ted.com/talks/amy_cuddy_your_body_language_shapes_who_you_are?language=en
And of course, because so many people struggle with this, Kathryn Schultz:https://www.ted.com/talks/kathryn_schulz_on_being_wrong?language=en
Being lonely is really hard, on a lot of levels. It can make people really neurotic. I think that a host of psychological ills arise from inadequate social support.