Bladder infections should never be fully treated at home. You need to see your Dr and probably have to get on anti biotics. While we don't want to get on them for minor infections that can heal themselves. Bladder infections left untreated can be very serious.
Cranberry juice does not cure bladder infections, it can help prevent them! Natrual isn't always the way to go if it is lingering more then a couple of days.
Eating yogurt daily, sitting in warm baths without soap, drinking cranberry juice the second you think you may be getting one can sometimes help, however if the infection worsens not gets better you need medical intervention.
Remember, people died of very simple illness before anti biotics as infections in the body can spread all over. So going to the Dr isn't a bad thing. Maybe talking in depth on why you continue to have reoccuring infections is something to address instead of just accepting you get them easily! Find out why!