I ghosted a friend and now i realize how terrible that is

3 years ago i began to feel uncomfortable around a friend. I didnt know what to do or how to communicate with them about it so i just ghosted her. I deeply regret it. I know i was a horrible person for doing that and i know how awful and traumatic for her to not hear anything from a person she considered a best friend and trusted with everything. I was so scared of conforntation that i chose to ran away and disappeared without any explanation. The thing is i didnt know that ghosted could hurt someone and traumatize them. I grew up in an unhealthy environment and none of my parents taught me how to defend myself and establish boundaries with ppl. I have always felt like others had a moral code or instructions on how to communicate but me. I genuinely did not know that what i did created harm and trauma. Im consumed by guilt and cannot believe i did that. Had i established boundaries and maybe confront her then none of this would have happened. I always try my best to be kind to people but i do it in ways that arent healthy. I would let people walk all over me and cross my boundaries i would let them hurt me and make me feel uncomfortable just so i can have friends because i didnt have many i cant communicate with people. My parents never taught me. I want to fix things now but i dont know what to do. I already apolagized and explained myself, they accepted the apology but still guilt hunts me every second. I cannot sleep or eat not even study. I feel like i deserve since she must have felt like this or even years dur to my radio silence. I regret it so much i feel shame and guikt on deep levels. But i didnt know i was oblivious i was always taught to lie and ran away because growing honestly led to more damage. I lied to ppl to be kind and not hurt them but its doing the opposite. Its not fair everyone knows how to communicate but me.