Hi Raven
Please please please don't give up. I have suffered from PCOS and diabetes for the last ten years. I lost five stones (still more to go) over a couple of years. It does come off very very slowly, but don't be disheartened as it WILL come off.
As you are a veggie, you obviously can't do red days, which is what has worked for me, but what I do have is a small amount of wholemeal pasta, or even wheat free pasta, small amount of potatoes and sometimes rice and cous cous. I occasionally do green days to relieve me of my carb cravings, but even when I do, I don't have white pasta, it bloats me sooooo much.
I would suggest things like half a pack of ainsley harriot vege cous cous mixed with chunky chargrilled veg and maybe some quorn chunks, small portion of sw chipes (one 200g potatoes worth) with egg, beans etc. Try making potato cakes with either smash or fresh mash potato, mixed with half cooked veg (grated carrots, diced onion, peas, sweetcorn, courgette and shredded cabbage) and hex cheese, fry quickly in frylight then put in oven for 15 mins. Using lots of veg and the cheese will reduce the amount of potato you have. Quorn curry with vege rice.There are lots of other things I could suggest, but I've probably rambled enough!
No disrespect to your consultant, but it is near on impossible to sustain a diet without any carbs and in my experience and opinion is totally unnecessary. Just remember, small portions, twice a day, of potatoes, rice and cous cous, limit your bread (even wholemeal) and don't eat white pasta, it's the worst culprit when suffering PCOS.
Hope this helps little, please stick at it, my symptoms are a lot lot better and the pain nowhere near as bad.