Hurt and Confused

I was dealt a harsh blow today.  I have been friends with this person for a couple of years and a month ago we were making wedding plans and discussing her being my maid of honor.  In just the last few weeks have felt that things have been cooling off.  She has canceled plans at the last minute, doesn't call and doesn't want to talk when I call.  Finally this morning I left her a phone message asking if I had done something wrong and if we could talk.  A few hours later I received a facebook message that basically said "I don't want to be friends anymore".  I am thoroughly hurt and confused by this whole course of events.  Despite claiming a desire to spare my feelings the message contained several comments like "you have been very needy and dramatic, to the extent that I don't want to answer the phone when you call because I know what I am in for" and "At times you can be a know-it-all" and when referring to my recent engagement "Just remember, the shine on the diamond fades and you only wear the dress for one day, so you better be sure of what you want".  I realize that I have my faults, but this friend has never brought up any of these issues before.  I am so devastated by the things she has said that it has left me wondering which parts are true, am I this horrible person that she paints me to be?  How could a friend of several years just up and walk away rather than try to work things out?