there are MANY reasons people have a bad day at the range.... lack of focus, physically or mentally tired, pain, weather blah blah blah.... and none of them is permanent.
this is why we practice.... because we will not always have a good day in life much less the range.
what i do when i have the days that i cant hit a thing is i start from a much closer position and go back thru the basics.... stance, grip, breathing, trigger squeeze. when it starts working good, i increase the distances again incrementally till i am at the range i usually practice at.
if it doesnt come together, i dig out the .22 and a couple of boxes of ammo and blow holes in paper plates.... it can be about just having some fun too.
it will get better another day.