Rheanna, I know it feels like forever, but she's still really really small!
My first one was like this until age 6 months - what you described about the quivering as you enter the restaurant was exactly what I remember with him. The mall, restaurants, people's house - meltdown city. It did get a lot better after 6 months old.
DH and I still are mystified by these little babies that are happily sleeping in restaurants - neither of ours were like that.