I decided this was too important to just add to my other response, so here goes.
Janet, we all have parts of our parents in us. It is called genetics. No avoiding it. However, what we do with those genetics is what matters. I have my father's eyes, my mother's coloring. I have my father's sense of humor, my mother's temper. My mother's legs and teeth, my father's mouth. My mother's coloring does not go well with my father's grey-green eyes, so I died my hair and use a fake tan to make them blend together. I love my father's ironic sense of humor and have worked to develop it to the best of my ability. My mother's temper is not something to be reckoned with and I don't ever want people to live in mortal fear of me like I did of her when I was a child. I learned to control my temper and when I feel it flaring, I leave the situation. My parent may be a part of me, but they are NOT me.
Your parents are a part of you but there is no question in anyone's mind (even a vindictive, bratty, mean-natured snake like Cory) that you are not your mother. You worked hard to never be her. You took her genetic makeup, her abuse, her cruelty and turned it into a kind, loving, intelligent woman. Yes, you have problems and issues. We all do. Your faults may have been caused by your mother but they are your faults and not anything like what you have described.
You have put yourself so many steps above your mother and your childhood that you should be holding yourself up with pride, not listening to the words of a thankless child who was out to hurt you. For Cory (like my child and many here), the best offense is a very nasty defense.
If he could get you to deflect from catching him rolling a joint to saying things that he knew would set you off, he would and did. I doubt he believed them. He just wanted you to focus on something else. Sadly, he succeeded. Of course, it may have backfired (as so many of their impulsive schemes do) in that you no longer want to be near him.
Anyway, please listen to what we have all been telling you. You are not your mother. Not even close. You have overcome all that she tried to turn you into. You have proven time and again that you're the better person. Don't let some punk's words make you doubt yourself for even one second. You are a wonderful person (make that your mantra!). We all know and love that wonderful person.