diabetes

noticed the last few weeks that especially during the night I'm developing a huge thirst and I'm waking up 5 or 6 times a night to take water , I also wee and incredible amount but always have had , I pee about 4 or 5 times a night every single night through the night I'm a non smoker , not a huge drinker, couple of stone overweight, my last medical showed my blood pressure to be slightly high but the Doc recommended some lifestyle changes rather then medication, I've had 2 tests for diabetes from the my Docs over the years the last one in December 2013, both times negative, the usual story with my medical practice in Wallington is that there are no slots to see a GP for almost 2 weeks, should I be concerned?