Hi berrylover,
When you are first diagnosed it is quite natural to feel scared, angry and generally deeply ****ed off with the world. However, try not to - it really isn't so bad once you get used to it and there are even up sides! The immediate good news is that the symptoms (the thirst and tiredness etc.) are all caused by your high levels of blood glucose (BG). When you get this under control (which it is often possible to do quite quickly) these symptoms will go away almost immediately. If you make radical changes to your diet and start exercising more, then you might well find that within even a couple of weeks you will be feeling better than you have done for years. That is the big up side of diabetes - many people live really unhealthy lifestyles, and vaguely intend to do something about it "one of these days" (I know I did). However, that day never comes - you can always put the diet or the new exercise regime off until next week. Diabetes forces you to take this seriously, and the benefits of a healthier lifestyle go massively beyond keeping the diabetes under control.
An important thing that you should realize is that the standard of healthcare you will get from the NHS - as well as the quality of advice is wildly variable. The dietary advice that you have been given (low fat, low salt, eat complex carbohydrates with every meal) is very dated thinking. The reason that doctors, "diabetes nurses" and even many dietitians persist in handing out this advice, is that it is what is in the medical textbooks. Unfortunately the Diabetes UK publications that you have seen take this outdated advice and simplifies it. This "NHS standard" approach does help some people, but most people who follow it tend to end up on high doses of anti-diabetic drugs or insulin within a very few years. If you read research, or modern books on diabetes written by specialists, or even look around this forum, then you will get a very different picture. In short, as Fergus has already explained, carbohydrate restriction is the key to good BG control, and since everyone is different you need to learn what effect various foods have upon your body by getting a glucose monitor and learning how to interpret the results.
Fortunately, you have come to the right place for advice - there are a lot of very knowledgeable people here. Have a look around at past threads on this forum - initially concentrating on advice for the newly diagnosed (a good place to start is the
Newly diagnosed and so confused thread). At some stage it is probably going to be worth investing in a book or two. There are some great ones out there - and also some highly dodgy ones, so take advice on this. Personally, I think that the most useful book is probably going to be
Dr. Bernstein's Diabetes Solution. Richard Bernstein is both a diabetic and a diabetes specialist, who has done a lot of research in this area and is one of the great proponents of low carb diabetes management. He is very highly respected in the diabetes world, both amongst researchers and patients. His book (which is non-technical advice for diabetics, and very readable) is the bible of many on these forums.
Good luck, and keep posting