If you are getting more thirsty than you used to, and consequently drinking more and urinating more then this is definitely something that you should get checked out. It could be a symptom of diabetes, but equally it could be caused by many other things (some trivial, some serious). Go see your GP, explain your concerns, and ask to be tested for diabetes. If it isn't diabetes, then you need to find out what it is. If it is then don't panic! Just be aware that you will need to make some changes to your lifestyle and start learning how to control the condition.