DAMN IT see a doctor, you need this treated as fast as possible I don't think you understand how fast this can progress and cause bladder or kidney damage, every day you delay the more it can travel back up your system or even become life threating, this is not like a cold where you can just wait it out, go to a walk in clinic or an ER NOW!
changing your diaper ever 2 pees is irrelevant, keeping clean and hydrated is, I have been 24/7 for 17 years now and have only had 2 bad UTI's and I only change when I need to, if it's every 4 hours or once a day, the first UTI I had was just simply triggered at a ham fest where I did not drink enough and we where camping so I had not been able to clean correctly for 3 days.
Generally speaking the bacteria that causes the UTI comes from your ass/fecal stuff and if your not clean the environment in a diaper can help that bacteria grow, even if it's a dry diaper, when you do clean only move from the front to back, clean your penis first and then work down and backwards just a quick baby wipe is enough, powder and cream help with diaper rash but will do nothing for an active UTI.
staying hydrated, drinking cranberry juice and all the other stuff suggested helps prevent one, not treat an active UTI!
At the first sign of a UTI I call my doctor and he puts me on antibiotics, they don't even wait for me to come in, that how serious my doctor views it .