I hit my girlfriend last night with a stapler?

I am so scared, I don't remember much from what happened last night but, this is what I remember. I found out she had been cheating on me for 3 months. I then drank so much, I lost control, and went over to her house. I then confronted her and told her to give me head. She refused, so I grabbed the nearest thing in her bedroom, which was a stapler. I then hit her across the head with it several times. I don't remember what happened next but I woke up this morning near a dumpster with my wallet and mobile missing. I don't know what to do.