What should I do about an old friend that does nothing but brag constantly?

I've been friends with this girl for over 15 years. The whole time I have known her, she has always bragged about things, and basically tried making me feel bad about my life. She had a very bad childhood, complete with her own father & brother molesting her, so I think that might have something to do with this behavior. I have always excused it, because of her past. Her mother passed away from cancer when she was 23, and now she is 31, and has become a registered nurse. My life hasn't been so good either, but nothing compared to hers. I got addicted to pain pills, but have since recovered. I haven't been able to find a job, because of some trouble that I got into with the pills. Anyway, now, this "friend" calls me up and reminds me constantly that she is a nurse. She talks down to me like I am stupid. She really makes me feel bad about myself, and I think she knows it. How many times am I going to have to hear about her being a nurse? I swear, every time I talk to her on the phone she mentions her degree. BUT, when I try to talk to her about me doing good, going to the gym to lose weight, etc., she doesn't want to hear it. She quickly changes the subject, and turns the conversation around to herself. She has become a huge racist too, and is always talking bad about other people, and this has irritated me more than the bragging has. The straw that broke the camels back was when I told her an old friend of ours that just had a premature baby, and she told me, "Well, if they baby has problems, I don't feel sorry for her, because that is what she gets for being a dope head!" I couldn't believe what a ***** my friend has become. She used to do a lot of drugs too! For a nurse, she is an uncaring, cold, racist *****. Should I tell her something, and just quit talking to her? My own mother can't stand her. She told me to quit hanging out with her a long time ago, because all she does is say stuff to me to make me feel bad.