It would help if I had some more information on what you are lifting. However, after the first time you legitimately stall on the squat, I recommend a 10% to 12% deload, the insertion of a light day, and going back up in 5 lb jumps. The whole point is to allow yourself more recovery. No need to rush headlong into a wall.
Where did you get the idea that you only deadlift once every six workouts? That probably won't get you very far. When you are ready, deadlift once every three or four workouts.