I either need a different welding helmet, or I need to stop breathing.

If all else fails, go to the sporting goods store and buy a snorkel to wear while you use it.....lol. I have a cheaper auto darken helmet too. The auto darken part works great and I have no issues with fogging. My biggest problem is glare on the backside of the lens from the overhead lights shining into the helmet from behind while I'm welding.