Hello there,
The symptoms you are describing seem to be more like premenstrual symptoms which sometimes may extend for a week during you r periods when the levels of progesterone are low in the body. Als,o as you have PCOS you have been rightly advised to reduce sugar in your diet. What it means is to reduce simple carbohydrates and try to include complex carbohydrates which are slowly digested. This will help you to lose some weight and reduce the problems related with PCOS like irregular periods, unwanted facial hair, etc. Do not worry as there is no side effect of reducing sugars in the diet.
Hope this helps. Take care

Dear madam i can understand your concern.
i would like to explain about human physiology
in over brain there will be some thing called rewarding center this center will secret one chemical substance called dopamine.
This chemical substance will give you pleasurable feeling in brain.
this kind of feeling will increase with increase consumption of quantity of sugar and soon there will be increased in threshold of this rewarding center.
if the threshold id increased you need to consume more and more sugar to meet its demands.
It will take 2-3 wks to decrease the threshold and become normal.
but you need to focus on your will power to avoid taking sugar
the results will be better with time
all the best
Regards