Hi
@Mama J, and welcome to the forum. No need to panic, the pre-diabetic label means just that and it is sensible to treat it as a warning flag rather than a sign of impending doom!
You will have got the diagnosis in response to the result of a HbA1c value obtained from a blood test. It will be somewhere between 42 and 48. It is useful to get the actual value so that you know where you are, and you can see how it changes with time to see what progress you are making. The thing about the HbA1c is that it says something about your blood glucose control over the last 10 weeks or so and the full effects of your gym work and low carb diet may not have started to show up yet. So keep going!
In preparation for your visit to the nurse, read around the forum and check out the learning zone on the red tab above. Ask any questions you like on here, we have all been there and so question is considered silly. There will always be somebody with relevant experience around to help.