With such a topic so broad we truly try to cover the basics from all angles in this group. Nothing too big or too small. Nutrition is as significant if not more as exercise is to reaching your goals so learn all you can.
so... fill in the nutrition pages and start a diary here.
or if you know you need less fat and just want a figure to work too then follow the guideline this site gave me... 35grams of fat a day maximum. I only ever push it up to 50g if I have fish twice in a day.
I suggest changing one thing at a time even if it takes 6 years to make your lifestyle normal- i don't think the word diet is clever anymore so do it how you suggest as gradually. It is the best way and it doesn't matter how slow weight loss is as that proves it's a normal eating habit that wont spiral out of control as you wont need to finish dieting and then eat normally.