Sorry Ren, that sounds terrible. My mum had one a few weeks ago with blood in her pee and got really sick. So get to the dr ASAP! Drink lots of water and some cranberry juice, you can get cranberry tablets too, I find they work really well. Stops the bacteria sticking to the wall of the bladder and multiplying so good for preventing them but u need to get it treated also.
It doesn't have to sting. I had one in my kidney a few years ago and it didn't sting at all. Just sore in my back.