J.M.
I don't know if this will help you now, but there's stuff that you can get over the counter called AZO and it's amazing. It basically numbs your urinary tract so it doesn't hurt to pee. You need to take it with a little food or milk or it will give you a stomach ache, and it will turn your pee bright kool-aid orange, but it works wonders. You can even take it once you've started the antibiotics but before you start feeling some relief.
Feel better soon.