Hope you don't mind me butting in here, but I have a friend that's is exactly like yours. I also stopped trying to get in touch with her when she keeps breaking our arrangements. She tells me that I am the one who does not water the plant that is our freindship, but whenever I agree to meet with her, she cancels. I have tried to be there for her, but it seems that she does not hae enough self esteem to help herself... It's futile trying to help someone who doesn't care enough about themselves...

Trust that you need to look after your well being before anyone else's, otherwise, if you expend all your energy on another who merely drains you, you will have nothing left to give...