Dealing with Hallucinations in the ER

I’m in the ER right now with my sister. She has IBS like me, so we brought her in so that she can get some pain medication. This is really stressing me out, and my hallucinations followed me here. My monster is looking at me from the end of the hallway and it’s really scaring me, but I can’t do anything about it because I have to make sure my sister is taken care of before I worry about myself. He’s telling me to tear my skin off so that he can eat it. I try to tell him no under my breath, but he said it’s not loud enough. I obviously can’t shout at him like I want to because we’re in a hospital and he isn’t real. There was a psychiatric patient here too, so hearing him talk about his delusions only worsened mine. I’m really scared and don’t know what to do. Does anyone have any suggestions for coping at the moment? I don’t want to lash out because 1) my sisters health needs to come before mine right now, and 2) I don’t want them to throw me into another hospital for this. I just need to be able to cope for right now. Any suggestions?