Well... I don't know the answers to your questions. However here are links to 6 articles, from PsychCentral's archives, that talk about the impact of low self esteem & self-criticism on one's mental health along with way to build self-esteem... which is, I would presume, the antidote to self-rejection. Hopefully some of the information & suggestions in these articles can be of some help:

https://psychcentral.com/blog/how-do...dium=popular17

https://psychcentral.com/blog/how-to...s-and-success/

https://psychcentral.com/lib/self-es...that-can-help/

https://psychcentral.com/lib/what-re...-esteem/?all=1

https://psychcentral.com/lib/12-simp...dium=popular17

https://psychcentral.com/lib/bluepri...-esteem/?all=1