I went through a bad patch a very long time ago when I was about 17.  I did some stupid stuff and was just generally a POS person.  It only lasted about 18 months, but that period seems burned into my psyche and I just can't seem to forgive myself or mentally move past it.  All the stuff I did from other periods are long forgotten.   

I thought time would blunt it, but it hasn't.  The specific memories are fading but it's left behind this vague but powerful sense of shame and guilt and self-loathing about hurting people that I loved and being a very bad and self-destructive person. 

It just feels like no matter how old I get and whatever person I become, in my head I can never move past the sense that I'm still that same stupid kid.  

It's like my mind is haunted. 

Can anyone relate?  Does anyone have practical advice for how to move past things like this?