Hi Warren, I think you can gain a lot of control by making some changes to your diet. Some of the things you are eating are ringing alarm bells, I would take a close look at the packaging on your breakfast bar, I am almost certain it will be full of sugar and carbohydrates which will shoot up your blood sugars and then they will drop a while later when you will feel hungry again. Take a look at the carbohydrates in your bar, I think you will be shocked.
Next - fruit and crisps (sorry) both are high in carbohydrates, it would be better if you can avoid both. Perfect snack foods are ... slices of ham, cheese, pepperami, hard boiled egg, cherry tomatoes, cold chicken drumsticks etc. It also looks like you are not eating a lot early in the day, it might be better to balance your food over the day.
Suggestions for brekkie - yoghurt with berries. I normally get a full fat greek yoghurt, and stir in about 10 raspberries. Its really luxurious and quite filling. OR ... omelette, or bacon and eggs, or cold leftovers from last nights dinner.
Suggestions for lunch - ham salad, or cheese or chicken or hard boiled egg (you're getting the idea right) or if you didn't have one for brekkie, omelette, or any protein with veg if you are not a big fan of salad.
If you can I would cut in half your portions of potatoes, rice or pasta, these will make your blood sugar rise dramatically and controlling those ingredients will really help you to maintain control.
Have a read around the forum, particularly the low carb section, its quite an eye opener! Good luck