I'm sure you are hyping it up and making it sound super exciting and fun, so I won't even go there. :) Have you talked to his teacher about exactly what is going on at school re: anxiety issues. That's kind of a blanket statement and I'd want to get pretty specific. My DD (just turned 5 also) has loved preschool since she started at 3, but we had some issues getting started this year, too. She's in a Transitional K class and the teacher is def more strict (and perhaps more aloof - taking a more educational vs. nurturer role like she had in the other years maybe?) and 3/4 of her friends had gone to Kindergarten. So I think this contributed to my daughters issues getting started in the year. I tried to keep open communication with the teachers, and talked openly with DD about how she was feeling. I told her it was okay to feel upset (and gave her some coping strategies - like talking to me about it, or that she could give her teachers a hug, and her brother was right next door and she would see him on the playground, etc.) but that school was her job and it wasn't a choice. Finally within the last couple weeks, she's been feeling better and more confident. HOpefully you can have a good honest conversation with his teachers and figure out what is going on at school so you can start to help him cope with his strong feelings and make this transition a little easier. HUGS - it's so hard to see our kids having trouble. I was kind of surprised by how distressed I became over her upset.