Is it ok to walk away without saying anything?

I was with my girlfriend in my room late at night. I had to get up early the next morning for a track meet. As we start talking we get into an argument about our relationship and how its been hard because I have been really busy with school, work and track. She was also feeling stressed out about getting a job after college. I told her that I wanted to talk about it but it was late and I really had to get to bed. She stormed out without saying anything and is now even more angry at me. I am also angry at her because I was trying to work it out and didn't want her to leave.