I have had a lot of the same feelings you express, particularly fear of intimacy. In my case, the source was growing up with an alcoholic mother who had, I believe, narcissistic personality disorder. She screamed at me a lot when I was child, mainly when I dared to seem to disagree with her, and so I learned to fear saying what I thought, to fear being even slightly assertive, and to fear having people emotionally close to me. I also learned to go along with what others were doing, to become a people pleaser.

How was your childhood?

A traumatic experience (as you mentioned) can also cause the avoidance you describe.

Therapy helped me to get past fear and avoidance and become able to be close to appropriate others, to express and receive love, and to say and do what is on my mind. I no longer have that paralyzing fear of intimacy (romantic or platonic) or of asserting myself.

Have you tried, or would you consider, seeing a therapist?