I need womens answers thanks?

Ive been with the love of my life for over 4 years I just graduated college and going for my masters and my relationship has been bumpy for 6 months... But prior to that it was the greatest thing either of us had experienced. Just 2 days ago my g/f had just told me that she wasnt happy with me anymore and that she felt that she needed to end our relationship, so I just told her That I loved her and that I needed her and basically nice things and emotional things. I love her tremendously she is very emotional and impulsive and im scared that Ive really lost her for good. I was going to ask her to marry me at the end of the month :(. I treat her with respect, love and almost flawless. I know by giving her space its the best for her to miss me... I just want to know if its just shes upset about something, or is it just she was stressed out or what not because she was stressed out due to school the previous week, Just need honesty and truth thank you.