I have the same problem - the answer to everything you just asked is: it doesn't

You know what does?
Self forgiveness
Self love
Self respect
Self compassion

You have to be able to look at yourself and realize "yes, i made these mistakes" , "no, they do not define me as a person - i have other qualities too" , " yes, i can use this to help me grow and learn"

Then don't allow yourself to dwell - you can reflect on it from time to time when the memory becomes triggered, but you control how long you allow your thoughts to focus on it and what emotion you equate with it - one of remorse n pain or one of growth