Yes, I am a diabetic and the raging thirst/peeing a lot is a sign of elevated blood glucose levels, as is continual bouts of thrush.
Definitely speak to your GP, who should arrange either a glucose tolerance test (not sure if this is just if you're pregnant though?) or a fasting blood test to check your blood glucose levels. Even a urine dip test can be used as a first step.
If you can't get in to see your GP quickly, then if you know someone diabetic you could ask to use their finger prick glucose monitor and test yourself to see what your levels are (use a clean (new) lancet each time and wash and dry your hands thoroughly beforehand 
). You can then check 'normal' (non-diabetic) levels online and compare your results.
Or you could buy a glucose monitoring/testing kit at a pharmacy/online - bear in mind that the strips are quite expensive though! You could try and get some urine testing strips instead but I don't know if you can buy these over the counter or how much they cost.
In the meantime, try and increase the water you drink, and try and walk more, especially after eating a meal. For the thrush, cotton underwear, no tights or tight trousers, no highly perfumed soaps or bath oils and try and go commando at home as much as possible!
Good luck! As others have said it's important to get this checked as soon as possible, it's unlikely you would have the more severe symptoms unless your sugars had been high for a long time - eg if my sugars are very high I feel very sleepy and can't stay awake and my vision goes a bit blurry. Conversely, now I am well controlled my eyesight has actually improved and my glasses are less strong!
It's a lot to get your head around at first if you do find out you are diabetic but it is possible to get it under control (mostly) and decrease the possible side effects and affect it has on your life .