You have got a lot of problems, so now wonder you are p'd off with this latest diagnosis. However, it isn't anywhere near the end of the world and for many of us here it has been the proverbial kick up the bum we needed to get back on track with healthy eating and more exercise.
I am also a fussy eater so I understand your problem. I detest curry and most veggies so I've had to increase the ones I do like, such as mushrooms and tomatoes.
The first thing you should do diet-wise is ditch the sugar in the tea (get sweeteners) and throw the Lucozade in the river. That is like drinking liquid sugar. Some people use diet coke or fizzy bottled water but personally I just have tap water and 6 mugs of tea a day! Then have a look in your fridge and cupboards, pull out what you eat regularly and read the nutrition labels. You will be surprised how many carbohydrates you are eating. All carbs turn to sugar (glucose) once inside your body. The main ones to be careful with are potatoes, rice, bread, pasta, pastry, processed ready meals, anything with a lot of added sugar. You can swap to granary bread or brown rice if you can't do without them, but any of these must be eaten in small portions. Ditch the milk chocolate, try the 70+% dark. It's yuk in my opinion so I don't bother. Instead of having a plateful of potatoes, try reducing your portions to one or two new or roast spuds. Weight them first so you can calculate how many grams of carbs they contain. Your body may cope with them, or it may not. A meter will help you decide.
You can eat as much natural fat as you wish as this doesn't affect blood sugars, so go for real butter, full fat yogurts, real mayonnaise etc. This will all help.
Ask as many questions as you like. No question is silly. We are all in this together.