Walk away. I've found the more you fight it, more often than not (but not always) you're only going to magnify the problems. I do the same thing when I'm getting tired, or if I've just got done lifting. Because, for me, it's a major mental game. You can try to concentrate on the form, release, anchor, etc, but if you have a nagging sensation in your subconscious reminding you of all the bad shots that day, you probably are going to struggle all day. That's how I approach it. Although there were times, when I did what Rybo, and Ben did, and that's move into a closer range and concentrate solely on shot execution, but sometimes even that isn't enough (for me anyways).