I don't count calories but I do practice portion control because I also do not have a reliable "I'm full" signal. I weigh and measure everything. I also don't snack and have an absolute rule not to eat anything after 6PM. Usually I don't eat anything after mid afternoon except perhaps for a cup of broth. The calorie deficit idea is not a good one to base your eating on because the body does not treat all calories the same. Just try to figure out what seems like a reasonable amount of food to eat and stick with it. It takes discipline and commitment but eventually it becomes habit or at least it has for me.