Sounds like to me your tired, as soon as my arm gets tired my groups go out the window and i start getting stray arrows. I recomend waiting an hour then trying to shoot a 3 arrow group at 30. See what happends, If you still feel tired stop shooting and take a break and then shoot another 3 arrow group, if its still off at 30 yards id say for tommorows hunt id limit myself to 20 yards.