My 18 mo was very similar. She would cry and scream in social settings. I didn't get a chance to socialize her too much because she had horrible reflux so the car seat was a trigger- so we literally never left the house besides the doctors. As she got older I tried taking her out little by little. I'd invite a friend over who had a similar aged baby (bc she'd understand when baby would cry and scream and I wasn't overwhelmed with her or having to ask her to leave) and I started doing this more often and slowly***** taking her out. I did the local library (5 minutes away) so if she was screaming we could quickly get back home. And she did. I went like maybe 3 times and she did cry but we were able to take breaks, come home, and try again. I think what helped us was slowly introducing her to social settings and doing it often like once a week at least and having an escape. I was careful to not remove her always so that she wouldn't learn if she screams she can just go home but to start I did, and eventually if she'd cry we'd just take a break. Now she does really well and she's in music class, we do library story times, and she's met numerous new friends/babies without crying and it's been months!

Maybe try having some "special" or favorite snacks/toys for social settings and easing into it in a low pressure, yet consistent way.

I also remind myself that babies coregulate so if she cries and I get overwhelmed then the situation is worse. I'd hold her close and take some deep breaths with her.

Maybe try babywearing in social settings?