Mutual love and respect are key to a successful marriage, in addition to a foundation built on layers consisting of Christian principles, a solid friendship, chastity, attraction, and fortified by faith. If the degree of her rudeness is intolerable, you should probably end the relationship because persistent negative character traits are difficult to extinguish. It is of extreme importance for a couple to have the sensitivity of not offending each other. Sharp words and criticism can damage a relationship. Every person has some peculiarities that may spark every now and then because of culture, environment, and upbringing. However, consistent inappropriate mannerisms need to be addressed from within. This is referred to as, "second order change," meaning that not only the behavior changes but the underlying principles are also altered, thus, producing new behaviors which are more enduring.
This is a good opportunity for you to examine your own behavior. Rudeness can be a reaction and a defense mechanism. Could you be provoking her to anger or jealousy? Are you giving her mixed messages or are you being passive-aggressive? Discuss your feelings and concerns with her honestly and give her the opportunity to ask the same of you. Perhaps she will reveal some of your traits that may be annoying her and which may in fact be making her respond rudely. Agree on a plan of action based on these principles. If one or both of you cannot commit to making these simple changes for the sake of making each other happy, how then can either of you commit to a lifetime with unforeseen challenges?
In any case, this on/off relationship is lingering on too long. Serious relationships require work. Before you can commit to each other, you must first be willing to commit to resolving weaknesses in your own character and promise to always strive to make the other happy. Otherwise, you are wasting each other's time and should just move on.