By going to the gym every day, eating less calories that you need to maintain your weight, and thus losing weight deflates the fat cells which can then function better.

You need to talk to a well trained endocrinologist. There is no approved way to alter leptin. PCOS is a form of pre diabetes and by sensitizing your cells to your own insulin you may lose weight. See guidelines for treating pre diabetes

This is not a easy question. We know so little about leptin & all its effects & sensitivity to it. Continue the exercise program & talk to a dietician about your diet. The YMCA has an excellent program for diet & exercise at a fairly cheap price. If you have an available Y, this a good place to start. You have PCOD, but did not tell me if you are on drugs. Some help with wt. control & some have the opposite effect. Talk to your Dr. about your medications & get adjusted if needed.