I don't buy anything I don't want to eat. If it's in the house, I'll likely eat it. So, resist any urge to buy things you don't want to eat (or do want to eat, but don't want to want to eat...hehe!). That means no candy, cake, cookies, brownie mixes, soda, juice, etc. I drink only water and eat no sugary foods (excpet on bdays).
I'd look into PCOS and find out every bit of detail about it that you can. Find out how it affects your systems and the relationship to diabetes (there is one, from what I understand). Learn about diabetes too (if it is related) and read all the awful, horrible stories of what happens when diabetes goes bad. Then when you feel a craving for those chips or cake or cookies, think back on those stories. Associate those things with those stories because they ARE linked. You will be there one day unless you manage to get it controlled (which I know you can!). My sister had PCOS for several years and was just diagnosed with diabetes last year. She did nothing healthwise when she was diagnosed with PCOS. She didn't change her diet, lose weight, or anything. She now had full blown diabetes and is really struggling. She is having issues with her legs and if she doesn't get it under control, she might be one of those who starts losing part of their feet! This could be you. (so think of that any time you want some ice cream...)
Another thing to consider, which isn't the most ideal, but if it'll help offer some control, it's a good idea...anyway, you can pick ONE day a week that you can get those cravings out. So, every Saturday, you can eat whatever food you want. I had a friend that was 400 lbs. He got down to 190 lbs from working out and controlling his eating. He had one day a week that he ate whatever he wanted. While it's not ideal, it DID help curb his poor eating habits and helped him eat healthier much more often. If he hadn't done that, it would have probably felt too far beyond his control, and he would have ended up eating crappy way more often and not losing the weight like he wanted to.
Good luck!!
Oh, and someone below made a good point, your taste buds will change given enough time. Healthy food will start tasting yummy...