Some people are just plain thoughtless and rude, unfortunately, but ask yourself this: ~ Do you really want to be friends with someone quite this thoughtless and rude?
She could never be a true friend, so consider yourself lucky to have discovered the truth so soon.
I tend to think that if someone is unpleasant, it is best to respond politely, but not to let them get close again. However, there can be occasions when people are nasty because they are going through a bad time ~ that's different, of course.
As for yourself, you probably need to be more assertive.
Do something which will increase your confidence: self-defence classes, amateur dramatics, first aid ~ something like that.
Consider what your real interests and likes are, and follow them ~ find true friends with similar interests.