Here's my problem, I used to be really close to one of my friends then she betrayed me and told secrets to people that weren't even true. Then we got in a huge argument and a week later after that she decides to talk to me and says we should have lunch to discuss what happened. Well we had lunch and we never did discuss it with me and she never apologized, she just said that she was ed up that day. We never really hung out after that day and everyone says she changes once she gets a boyfriend, which I have noticed too. She just forgets about her friends when she starts dating. Well one day out of the blue she starts talking to me again ( this was about a month or two later) she's like can we have breakfast together tomorrow, I say yeah that would be great. The next day comes and she's like oh I'm sorry I forgot I have to go to the doctors. After that day she just texts me once in a blue moon. Should I tell her what's wrong or should I just be a friend and act like everything is OK when it's not. I feel like I'm just a back up or something because she texts me sometimes and says I really need girl time and blah blah blah. So I feel like I'm only there when she wants me to be there.

Have a talk with your friend. Don't let another meeting go by without discussing your feelings, then leave it alone. All you can do is say how you feel. What she does with that is up to her.