There's a great book you should read, if you can get it in the UK: Patient's Guide to PCOS
PCOS is tricky, because it does come in a variety of forms and you'll have to play around with food, exercise and possibly even medication to figure things out.
The most general recommendations for PCOS/IR is to treat it with diet and exercise. The diet is supposed to manage your blood sugar levels, so it general is low carb (or rather, healthy carbs) and exercise helps your body handle the excess glucose (burns it, instead of driving your blood sugars up = IR).
I've had PCOS now for almost 20 years (at least diagnosed almost 20 years ago) and I've been managing my PCOS without medication, only through exercise and diet.
I do eat low-carb because that's what works for my body. In conjunction with that, I also work out almost every day (my day off is Friday unless I am traveling). I take a number of supplements, which you may want to take a look into, which help PCOS -- Vitamin D3, Chromium, magnesium, and zinc. Some studies have shown we are more deficient in these than your normal person.
Generally, when a doctor -- and others -- say it's a no carb, low carb, it's because they want you to avoid the sugar-laden carbohydrates like cakes, cookies, pies, bread, white rice, french fries, candy bars, etc. All of those will raise your blood sugar levels and if you have IR, you'll have a hard time bringing them down.
But, that doesn't mean that you're on a no carb diet. The best diets for PCOS are full of vegetables (all kinds!), some whole grains, and proteins and fats. Proteins and fats are important because they balance the blood sugar spikes. If you eat an apple, for example, you should eat it with a protein or a fat -- 2 oz of ham or almond butter.
If your doctor required you to not eat fruit, it's probably because of the high glycemic levels they have -- but there are fruit that are perfectly acceptable, if you combine them with a protein or fat. Apples, all berries (blueberries, strawberries, raspberries, etc.), and other low glycemix fruit work.
Here is a link for the glycemix index: http://www.health.harvard.edu/newswe..._100_foods.htm
The lower the number, the better for you. Of course, chances are, what you may crave are the ones with the highest number.
Additionally, more recent studies seem to indicate that there is a connection with PCOS and gluten sensitivity, so now the trend is to say that PCOS patients should try to eliminate wheat/gluten products. You can try that and see if you feel any different.
For better or worse, you'll have to be your own best advocate because there are very few experts on PCOS and patients are different and react differently.
Good luck. I know it's a lot of information and a lot to process.
P.S. Regarding the nutritionist... please be careful. All the nutritionists that I've paid to see (2 in total) have known nothing on PCOS and have always steered me to high carb diets... this has proved disastrous... I had my A1C show up at 5.8 after this advice. That's partly because a lot of dieticians haven't been updated to the latest and greatest in the studies or the disease.