Hi Roger and welcome to the forum.
I think there is some confusion because you've stated your fasting glucose test result as 7.1%. A fasting test is not expressed as a percentage but as the amount of glucose in your blood, expressed in minimoles per litre or mmol/l. An HBA1C test is very different to a fasting test and shows an average of your glucose levels over a 3 month period. It is always shown as a % and a figure of 7.1% would be quite high and would definitely show diabetes.
If your test was a fasting test then the clinical guidelines for this are "A level of 7.0 mmol/l or more after an overnight fast indicates that you have diabetes." Hence with a reading of 7.1 you can see why your new GP says you are borderline. I expect your GP won't prescribe medication yet but will want to see if you can maintain a level of around 7mmol/l just on diet. Sue is absolutely right about getting a test monitor. Even if you just test a couple of times a week, at least you will be able to see how your sugar levels are doing and make adjustments to your diet accordingly.
When you say you have been on a controlled diet, what type of diet is it? If it is a low carohydrate diet, then perhaps 7.1mmol/l is a little high. If it is not a low carb diet then you could probably reduce your blood glucose level simply with a small reduction in your carb intake. Nobody wants to be diabetic but you have to be aware that, whether or not you want to regard yourself as diabetic right now, your body is telling that you need to be careful from now on.