Coworker assaulted me at work

A male coworker and I would only talk when I was intoxicated and would Snapchat him and flirt and be sexual. Otherwise I didn't want him because he's a cocky jerk and I think he thinks I'm an easy lay. A few times he's asked me to give him head and I always say no. Last night he asked me to meet him after work and basically hook up. I said no maybe another time. Tonight he had me come meet him privately at work and kept grabbing my hand and putting it on his penis through his pants and would kinda grope my chest a little a few times. And he begged me over and over to put his penis in my mouth just for a few seconds and I said absolutely not and left after a couple minutes. When it got close to the end of the shift I started to have an anxiety attack and now I'm still pretty bothered by it. I just don't understand how he thought that was okay.... I'm not going to report him. No proof. I just idk need some emotional support.