what do I do about my 6 year old who get stressed out everywere we go?

My daughter will be in first grade this year. Half way thur school last year we noticed a change. Emma has always be very out going. Always talked to everyone. Now she is scared to eat around people or go anywere. This summer we did bible school. She wall flipping out. She has done this for 5 years. She used to look forward to it. She would not eat the snack at all. Emma always was very scocial. She would go out of her way to sit with people at church that were alone. Now she is suck to me like glue. These are people she sees alot. She seems very stressed out. I have a large family, none of them have gone thru this with there kids. I fell like I have failed Emma somehow. I don't know what to do. She doesn't want to go back to school. She says that she hates school. She has a hard time going to both of her grandparents houses. Never was this a problem. Help me!