Why is my Endless Summer Hydrandgea wilting?!?

We planted this hydrangea bush on Thursday the 2nd. The "growing tips" card it came with said it required full sun. So we planted it in a spot along the fence that gets sun from 8:00am until 3:00 in the afternoon that gets full sun. We water it everyday. It was planted in potting soil and dirt mix. It is only a mere 5 days since it was planted and its beginning to wilt! The leaves that were bold and green are shriveling up and turning brown, and the petals have dried and are falling off. We have done research and seem to be getting conflicting information. Does anyone know how tofix this problem? We are in a 5/6 zone. Thanks!