I can't give up on bread or potatoes either nutcracker.
Based on what you have put down this is my suggestion (based round WW):
Breakfast - stick to ceraels but use semi or skimmed milk
Lunch - swap sandwiches to salad with a small cub e of cheese; ideally try to work on swapping cheese to something else - maybe olives, seafood, very light cheese for sipping cucumber into, reduced cal coleslaw, lean meat slices (such as chicken, turkey, etc.)
Dinner - sounds okay but reduce amount of potatoes to just 2 or 3 small ones, or have baked potato or 2 scoops of mash (without fats and oils); make sure chicken in not fryied or done with creamy rich sauce.
And no crisps and biscuits. Really you have to try and avoid snacking at all. If you can't then choose to snack on fruit and vegetables.
Give yourself a little treat each day too - maybe a glass of wine, meringue nest and yoghurt/half fat creme fresh., etc. WW do some good range of naughties - like cake bars, etc. although I know Asda's own range is just the same number of points and cheaper.