Back off, buddy. Sit on your couch for at least five or six days.
I just did the couch thing. I had been doing a four on/one off split for about three months straight. For the last week, I felt shitty, verging on sick.
Last Tuesday, I went in for leg day, did two sets of warm-up squats, re-racked the bar and went home. Why?
Because I: a) felt how you feel; b) was struggling with 135 lbs when the week before I did 10x3 with 315 (first time, yay me!); and c) I had the nagging feeling that I was going to hurt myself. Now, I'm not going to speak for anyone, but I bet people will agree that it's when you think you're going to hurt yourself that you do.
Go home, sit on the couch. Went back for the first time today and felt great. Put up more weight than usual and didn't have any of the usual little dingy injuries.