Hi Tony and welcome to the forum.
Well, you have taken the most important decision - to take control of your diabetes and not let it control you. Also the second most important decision - to join us!
Your BS is pretty high according to the GTT result, but not so high that your GP should want to whack you straight onto oral meds without giving you the option of improving things with diet. If immediate meds are suggested then you should suggest that you would like to have a go at diet control and exercise for a couple of months and then review the situation.
Not sure where the BS 50% reduction from a 10% weight reduction came from. What the weight reduction will do is reduce your insulin resistance, and the generally accepted figure is that a 10% reduction in weight will result in a 1.0mmol reduction in BS, not 50%. But of course you will only achieve the weight reduction by a change in diet, and it is the diet that can halve your BS, provided you choose the right one of course.
Don't be surprised if, when you see your GP, you are given the standard dietary information to ensure that you eat plenty of starchy carbohydrates with every meal. This is the government's recommended dietary advice, so your GP will simply be following the party line by telling you. But it is now widely accepted that this is not a good diet for a non-diabetic (and is quite likely the cause of the national obesity "epidemic"), but more importantly is a guarantee of high blood sugars and future complications if followed by a diabetic. If you need any advice on how best to control your diabetes by diet then please ask and one of us will be glad to help you.