//I have decided that i will give it six weeks, and if it's no better, I will return to sugar,//
This is where dieters can sometimes wrong.
If you cut an item out (2.5 x 7 = 17.5 teaspoons a week - don't ask me how many calories that is) your appetite will attempt to compensate for the loss. You might up your intake of meat, veg or bread by an amount that's too small to notice but, over the 6 weeks, becomes habitual.
If you then restart the old behaviour *and* maintain the adjusted interim behaviour then your total energy intake has increased and you'll gain weight. Barely perceptible gains, but they accumulate over longer periods, as everyone who wondered where their middle-aged spread came from knows, to their cost. ;-)