Boyfriend popping up , advice needed

Today, my boyfriend and I had a disagreement. Well technically it was lastnight. And I felt he was with someone else because of the was he was acting so I just said “it’s okay, or alright” one of those. He knew I was working that night because I told him so after him calling 10 times and me not responding and texting me 3 times next thing I know he was at my job, confronting me about why I didn’t text him back and he told me that I better do this or that or that he would beat my fucking ass. And then he asked why I was upset. Then he was in the parking lot watching me through the lot for a good 30 minutes. And then I couldn’t really text because I was working and so he left and drove by the parking lot 2 different times in 2 hours and accused me of fucking other people on my break.

I am so frustrated right now. My co worker keeps calling me stupid and an idiot for talking to him, but how would I know!! I feel highly disrespected and I don’t know what to do. It’s like he keeps projecting all his insecurities onto me. I’m not cheating but he probably is.

Advice please. We have been dating for a little under a month.