Umm its really fucking hard. I understood rationally for decades that i should "love myself " , but it wasnt until the last 3 years of compounded trauma that really drove me to self-examine and find out WHY rather than constantly looking outward.
Meditation is a start, to learn how to put more distance in between yourself and the false beliefs .
Maybe start diagramming , in order to connect the dots with what happened > what that made you feel about yourself. That way helped me to see through some illusions .
Maybe start with this book and workbook:
Healing The Child Within: Discovery and Recovery for Adult Children of Dysfunctional Families https://www.amazon.com/dp/0932194400/ref=cm_sw_r_cp_api_fabt1_zgBQFbHMF3RZG
Just wanted to add. You are wonderful just the way you are. You deserve to be around someone as a friend or partner that makes you see more of the value in you, not cause you to question yourself! If you have a parent with BPD you have spent too much life familiar with a false you that is wrapped up in shame and self-criticism. You deserve to get to know the real you (alive, free, full of love for yourself and the right others) that is just waiting to get out once it is safe enough. You deserve to surround yourself by safe people who make this possible. This is a great book: https://www.amazon.co.uk/Healing-Child-Within-Discovery-Dysfunctional/dp/0932194400
This #1 best seller is a brief but comprehensive explanation of what self-help books should be helping you to do. The perspective it gives you is very helpful in getting your bearings if you are new to self-help.
I would highly recommend reading "Healing the Child Within" or "Facing Codependence". The first being number one on my list. Understanding healthy boundaries in relationships makes a huge difference.
https://www.amazon.com/Healing-Child-Within-Discovery-Dysfunctional/dp/0932194400
https://www.amazon.com/Facing-Codependence-Where-Comes-Sabotages/dp/0062505890/
Just commenting to say I know where you are. My INTJ friend has stuck with me through some honestly crazy times, and she's always seemed to encourage me to accept myself rather just judge myself unfairly.
I've also found reading about the "authentic self" particularly helpful, as well as doing activities that encourage you to get more in touch with your inner voice - such as tarot, where you're reflecting and reading deeply into your own psyche, meditation, and tapping accupressure points with affirmations- what I try to practice is something called Emotional Freedom Technique which some people say is too new-agey but I find really helps me let go of emotions that build up or don't belong to me.
Have courage and faith in yourself. Find INFJ role models to help you appreciate your unique charm ;)