Are you using something like MyFitnessPal on your smartphone/computer to track your food intake? This App helped me learn where carbs exist in foods that I didn’t realize.
One item many discover is to avoid milk. (Mild contains lactose, a sugar.) cheeses (in moderation) are OK, as is Heavy Whipping Cream (HWC).
One sure way to tell if you are in ketosis is to measure your ketones. An inexpensive approach is to use pee strips (but this approach has limits on accuracy over time.) A better approach is to obtain a blood keto test meter (Keto MoJo are overall less expensive, Abbott Precision Xtra is another choice.) (When buying a blood meter, make sure to review the recurring price of the test strips.) A breath meter is a third way to go, but I believe is the most expensive.