Go to the doctor and get food allergy bloodwork... I was at a loss for years, turns out I was allergic to several foods I ate daily.
Elimination works, but takes forever. Bloodwork is easier.
Since you say milk and cheese helps you feel better, I wonder if you have a bacterial imbalance. There are a number of probiotics in milk and cheese which aid with digestion. Perhaps buy a bottle of probiotic pills and see if that helps with stomach upset.
Stumbled into Primal due to food allergies, and subsequent elimination of non-primal foods.
Start Gluten-Free/Soy-Free: December 2012; start weight 158lbs, Ladies size 6
Start Primal: March 2013, start weight 150lbs, Ladies size 6
Current: 132lbs, Ladies size 2
26lbs lost since cutting the crap.