The weight gain when I had PCOS was extremely depressing for me. Nothing I did helped for years until someone introduced me to "Eat Right for Your Type" and "Cook Right for your Type". By "type" they mean blood type. It's not really a diet. It just basically outlines what foods people with certain blood types can properly process so it doesn't get stored as fat or cause other problems.
For example; I'm an "O" type so red meat is beneficial to me. I can digest it quickly and absorb the nutrients without storing it. But, cabbage it toxic to me. I can't digest it or absorb nutrients from it and it gives me gas. So, red meat is in my diet, but cabbage is out.
I only have "Cook Right" and found it extremely helpful. It lists foods by category so I know what is beneficial, what is harmful and what is neutral ... I used to take this list with me when shopping until it became second nature. It also includes some excellent recipes, categorized by blood type.
Once I was eating this way, I found myself feeling a LOT healthier and slimming down. My energy level went up and I started swimming because it wasn't hard on my body and was great stress relief. I lost weight and felt much better.
Don't know if this will help for you, but thought I'd share.