Hi @outlander .....
This question probably has a jigsaw puzzle answer.
I can only respond from my own ideas and experience, as you know, so others may tell you something else .....
First of all, I think everyone, or at least most people, from all backgrounds and all walks of life have experienced this. I know I have. We moved around a lot while I was growing up so I had to “break in” to new social groups amongst new people every year or so.
The one constant for me was that I had loving parents. Even though I was bullied at school and boarding school (from 12 yo) that was something that gave my self-confidence some stability.
People wiithout loving, supportive parents have had a shakier start, but true friendships or other strong family relationships can help to stabilise and rebuild this .... but there will be trust issues to get past too.
Its all in the baby steps @outlander, and learning to recognise who are safe people to lean on, and for them to lean on you ..... relationships being a two way street.
Most importantly for you at the moment is probably coming to terms with the understanding that these are “only” feelings ..... that is not to devalue them in any way, but for you to understand that feelings are vaporous .... shiftable .... they are not like a brick wall that you can’t get over and around. You can learn to rationalise with your feelings and begin to trust in yourself and others more ..... but it is a baby-steps process ..... little by little, like any skill-building.
I have to go to class, but I will look out for your response later today.
💜