Weight loss and control is possible with PCOS. I have it myself and struggled with my weight. I managed to reduce from 78kgs to 64kgs, through healthy, controlled eating and working hard in the gym.
Are you on any medication? I was put on Metformin years ago and although it didn't make a substantial difference to my weight, it helped control the condition and regulated my periods.
I would suggest adopting a Low GI diet (Glycaemic Index) Low GI foods generally have a figure of 60 or under, you can get a food list from your GP.
Low GI foods usually consist of unrefined Carbohydrates like brown rice, wholewheat pasta and brown bread, as well as fruit and vegetables low in sugars.
It is important also to exercise regulalrly, so even if you can't go to the gym, doing a combination of cardiovascular and resistance training, you can do lots of things at home and go for brisk walks and try interval jogs. (I'm a Personal Trainer, so please feel free to ask for tips).