I would advise you to keep a food diary and also record your just-before and 2-hours-after eating, blood glucose readings in it. Then you can see how you are reacting to different foods, and you'll begin to see whether there is any pattern emerging.
Keep it for a week or two (or more, if you're feeling okay) and then take it to show your GP. As you obviously know, there are more than just 2 types of diabetes, and you'll need this information to help with a proper diagnosis.
If your practice won't give you enough test strips for this on prescription, get as many as you can but also be prepared to buy some. This information is very important at this stage.
If you feel unwell, and your readings go too high or too low (over 15, or below 3.5
and dropping) call an ambulance. At the very least, call NHS Direct (does it still exist?). I'm sure you'll never need to do this, but it's as well to be prepared

.
If you think you may be having hypoglycaemic episodes (low BGs), carry some glucose tablets and take one or two if you feel unwell and your BG levels are below 3.5. Test again after 15 minutes. You should get your BGs over 4.
Let us know how you get on.
Viv 8)