Don't remember what you are using for equipment, your getting to much heat to your smoking wood, either pull out some wood, move it away from the heat so it is back to smoldering rather then burning. You can also preburn your wood so it is more like charcoal or lump. Good luck, hope this helps. Oh you might also choke off the air to the wood chips some if your temps are runnin to high.
As Rich said, relax, grab your favorite adult beverage, cut back on how much wood you use. There are so many variable. There are times when I have one chunk of wood and it creates white smoke and there are times when I have three chunks in and its tbs heaven.
Even though it's white as long as it's not billowing thick white smoke continuously you'll be fine.