Girlfriend Pulled a Knife on Me After a Heated Argument

I'm in a pretty messed up situation right now and I could really use some advice. I'm a 22-year-old guy, and my girlfriend is 26. We've been together for a while and up until now, things have been going relatively smoothly. But recently, we had a huge argument that got way out of hand, and I'm not sure how to proceed.

So, here's what went down: We were having a disagreement about our plans for the weekend. We had discussed doing something together, but she suddenly made other plans without talking to me about it. I don't mind her wanting to do something else, but we already made the plans, dates, so I just wanted her to come and tell me first. But then, things took a really dark turn.

In the heat of the moment, my girlfriend actually grabbed a kitchen knife and held it up. I was completely shocked and scared. I never thought something like this would happen, especially not with her. Thankfully, she didn't physically hurt me, but the fact that she resorted to pulling a knife just blew my mind. And no, I didn't do anything before she pulled a knife. I would never physically attack anyone for any reason, especially not a woman. We were just arguing, and then she pulled a knife in the heat of the moment.

I know arguments can get intense, and people say and do things they regret when they're angry, but this feels like a whole different level. I can't shake off the feeling of unease and fear that this incident has left me with. I love her, but I'm not sure if I can just brush this under the rug and pretend everything's okay. Has anyone been through something similar? How do you even begin to address this?