I don't know if there's any future to your relationship, but I do know that simply getting married won't automatically turn her into a different person. Unless something happens to change her, she'll have the same problems then that she does now -- which isn't a recipe for a happy marriage.
She needs to face the real reasons for her anger, and not excuse it by saying others don't understand her. Perhaps they don't, but the reason is because her anger (from what you say) doesn't make sense -- that is, there isn't any apparent reason for it. I'm not a psychologist, of course, but she needs to realize that her anger may be caused by deeper emotional issues that need the help of a trained counselor. (Ask your pastor to recommend one.)
The most important thing I can urge you to do, however, is to put your lives into Christ's hands. He can change our lives as we yield ourselves to Him. The Bible says, "Get rid of all bitterness, rage and anger" (Ephesians 4:31) -- and He'll help us do this as we confess our sins and ask Him to fill us with His love. Begin by committing your life to Jesus Christ, and urge her to do the same.
Then seek God's will for your future. He knows what is best for you, and even if this relationship ends, trust Him to lead you to the wife of His choice.